2 n d e d i t i o n

Encyclopedia of

Philosophy

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2 n d e d i t i o n

Encyclopedia of

Philosophy

6v

olu

me

MASARYK – NUSSBAUM

DONALD M. BORCHERT

Editor in Chief

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Encyclopedia of Philosophy, Second EditionDonald M. Borchert, Editor in Chief

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c o n t e n t s

v o l u m e 1PREFACE TO 2ND EDITION

INTRODUCTION TO 1ST EDITION

LIST OF CONTRIBUTORS

LIST OF ARTICLES

ENCYCLOPEDIA OF

PHILOSOPHY2 n d e d i t i o n

Abbagnano–Byzantine Philosophy

v o l u m e 2Cabanis–Destutt de Tracy

v o l u m e 3Determinables–Fuzzy Logic

v o l u m e 4Gadamer–Just War Theory

v o l u m e 5Kabbalah–Marxist Philosophy

v o l u m e 6Masaryk–Nussbaum

v o l u m e 7Oakeshott–Presupposition

v o l u m e 8Price–Sextus Empiricus

v o l u m e 9Shaftesbury–Zubiri

v o l u m e 1 0

APPENDIX: ADDITIONAL ARTICLES

THEMATIC OUTLINE

BIBLIOGRAPHIES

INDEX

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masaryk, tomášgarrigue(1850–1937)

Tomá' Garrigue Masaryk, a Czech statesman andphilosopher, and president of Czechoslovakia from 1918to 1935, was born in Hodonín, Moravia. His politicalcareer belongs to history; of interest to students of phi-losophy is the fact that he studied philosophy at the Uni-versity of Vienna from 1872 to 1876 under FranzBrentano. He spent the year 1876–1877 at Leipzig, whereWilhelm Wundt was his teacher and Edmund Husserland Richard Avenarius were fellow students. In 1879Masaryk became Privatdozent at Vienna, submitting DerSelbstmord als sociale Massenerscheinung (Vienna, 1881)as his habilitation thesis. In 1882 Masaryk became profes-sor of philosophy at the Czech University in Prague,where he soon made his mark as a politician and writer inCzech. Základové konkretné logiky (The foundations ofconcrete logic; Prague, 1885; German translation, Versucheiner concreten Logik, Vienna, 1887) and Otázka sociální(The social question; Prague, 1898; German translation,Die philosophischen und sociologischen Grundlagen desMarxismus, Vienna, 1899) were followed by books onCzech history and politics and by an extensive Russian

intellectual history, first published in German as Russlandund Europa (2 vols., Jena, Germany, 1913; translated byEden and Cedar Paul as The Spirit of Russia, 2 vols., Lon-don, 1919). World War I and the presidency of Czecho-slovakia put an end to Masaryk’s academic pursuits, but abook of memoirs, Svêtová revoluce (The world revolution;Prague, 1925; English translation, edited by H. W. Steed,The Making of a State, London, 1927) and Hovory s T. G.Masarykem (Conversations with T. G. Masaryk; 3 vols.,Prague, 1931–1935) by Karel Capek (English translationsby M. and R. Weatherall, President Masaryk Tells HisStory, London, 1934, and Masaryk on Thought and Life,London, 1938) reformulate his convictions impressively.

Masaryk was a practical philosopher who believedthat philosophy should not only contemplate the worldbut also try to change it. He thus had little interest inproblems of epistemology or cosmology. In his early lifehe reacted against German idealism and accepted Britishempiricism (David Hume) and French positivism(Auguste Comte). Later he argued for a type of realismthat he called concretism. In every act of knowing, hebelieved, the whole man takes part. Concretism acknowl-edges not only reason but also the senses, the emotions,and the will—the whole experience of our consciousness.It is something like William James’s radical empiricism

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without the exceptional experiences admitted by James.But Masaryk’s main interest was in sociology and philos-ophy of history.

Masaryk’s realism was combined with a deep reli-gious belief—Masaryk was a theist who found the Uni-tarianism of his American wife congenial—and a strongconviction of the immutable difference between right andwrong. Masaryk’s thinking centered on the crisis of civi-lization caused by the decay of religion. He diagnosed thediseases of modern man (indifference, suicidal mania,violence, war, etc.) and prescribed remedies for them. Hebelieved that sociology is the foundation of any furthercultural advance but that its method must not be purelygenetic and descriptive. Teleology, or explanation by pur-pose, is legitimate. The aim of history is the realization ofthe ideal of humanity. Masaryk’s humanism was not,however, merely humanitarianism, although he oftenspoke of democracy as another term for his ideal. In spiteof his sympathies for the concrete demands of socialism,Masaryk remained an individualist who disapproved ofall forms of collectivism. He criticized Karl Marx as ablind worshiper of determinist science. Nevertheless,Masaryk exalted the role of the right kind of science. InZákladové konkretné logiky, his philosophically mostambitious book, he classified the sciences and showedhow they are internally related and coordinated. The taskof philosophy is to create a worldview based on the resultsof the sciences. Masaryk desired a new “Advancement ofLearning” that would save man from intellectual andmoral anarchy.

Masaryk assigned an important role in the realiza-tion of his ideal to his own nation, the Czech, and inter-preted its history, remembering the Hussites and theBohemian Brethren as a preparation for this task. Hethoroughly criticized Russia for being a breeding groundfor all the European diseases, particularly romanticismand materialism. Fëdor Dostoevsky, whom he bothadmired and rejected as a thinker, was a lifelong concern.Masaryk always expressed the deepest sympathies for theEnglish and American tradition of empiricism andmoralism and, in politics, turned his nation resolutelytoward the Anglo-Saxon West. In 1918 he liberated theCzechs not only politically but also intellectually.

See also Avenarius, Richard; Brentano, Franz; Comte,Auguste; Dostoevsky, Fyodor Mikhailovich; Empiri-cism; Humanism; Hume, David; Husserl, Edmund;James, William; Marx, Karl; Philosophy of History;Positivism; Teleology; Wundt, Wilhelm.

B i b l i o g r a p h yFor information on Masaryk as a thinker, see the bibliography

and articles in Festschrift Thomas G. Masaryk zum 80.Geburtstag, 2 vols., edited by B. Jakowenko (Bonn, 1930); W.P. Warren, Masaryk’s Democracy (Chapel Hill: University ofNorth Carolina, 1941); and René Wellek, “Masaryk’sPhilosophy,” in Essays on Czech Literature (The Hague:Mouton, 1963).

René Wellek (1967)

mass

The mass of a body is its inertia or resistance to change ofmotion. More precisely, it is a property of the body thatdetermines the body’s acceleration under the influence ofa given force. Mass can therefore be measured either bythe amount of force necessary to impart to the body agiven motion in a given time or by the acceleration pro-duced by a given force.

The absolute metric unit of mass is the gram, whichis the mass of a body whose velocity increases by one cen-timeter per second each second if acted upon by a forceof one dyne. Other common units are the kilogram(1,000 grams) and the pound (453.592 grams). For veloc-ities that are small as compared with the speed of light,the mass of a body is a constant, characteristic of the bodyand independent of its location—in contrast to weight,which varies with the body’s place on Earth or in the uni-verse.

Although fundamental to science and, together withlength and time, the basis of all measurements in physics,the concept of mass was unambiguously defined only atthe end of the nineteenth century. However, its rudimen-tary sources, systematically employed long before by IsaacNewton and to some extent already by Johannes Kepler,can be traced back to early Neoplatonic ideas concerningthe inactivity of matter as opposed to the spontaneity ofmind. The ancient metaphysical antithesis of matter andspirit served as a prototype of the physical contrast ofmass and force.

concept of inertial mass

Antiquity, and Greek science in particular, had no con-ception of inertial mass. Even the idea of quantity of mat-ter (quantitas materiae), the antecedent of inertial ordynamic mass, was foreign to the conceptual scheme ofAristotelian natural philosophy. Paradoxically, it wasNeoplatonism and its admixtures of Judeo-Christiandoctrines, with their emphasis on the spiritual and imma-terial nature of reality, that laid the foundations for the

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inertial conception of mass, which later became the basicnotion of materialistic or substantial philosophy. Toaccentuate the immaterial, sublime source of all force andlife in the intellect or God, Neoplatonism degraded mat-ter to impotence and endowed it with inertia in the senseof an absolute absence of spontaneous activity. For Ploti-nus, Proclus, Philo, Ibn Gabirol, and the Platonic patris-tic authors, matter was something base, inert, shapelessand “plump,” attributes that reappear in Kepler’s charac-terization of matter as that which is too “plump andclumsy to move itself from one place to another.”

The idea of a quantitative determination of matterdifferent from, and ontologically prior to, spatial exten-sion originated in scholastic philosophy in connectionwith the problem of the transubstantiation. The questionof how accidents of condensation or rarefaction (volumechanges) can persist in the consecrated hostia of the holybread and wine of the Eucharist whereas the substancesof the bread and the wine change into the Body and theBlood of Christ led Aegidius Romanus, a disciple ofThomas Aquinas, to the formulation of his theory ofduplex quantitas. According to this theory matter is deter-mined by two quantities; it is “so and so much” (tanta ettanta) and “occupies such and such a volume” (et occupattantum et tantum locum), the former determination, thequantitas materiae, having ontological priority over bulk.Aegidius’s early conception of mass as quantity of matter,expounded in his Theoremata de Corpore Christi (1276),was soon renounced and had little influence on the sub-sequent development of the concept of mass. It was pri-marily Kepler who ascribed to matter an inherentpropensity for inertia in his search for a dynamical expla-nation of the newly discovered elliptical orbits of plane-tary motion; in need of a concept expressing theopposition intrinsic in matter to motory forces, Keplerformulated the inertial concept of mass. In his EpitomeAstronomiae Copernicanae (1618) he declared that “iner-tia or opposition to motion is a characteristic of matter;it is stronger the greater the quantity of matter in a givenvolume.”

A different approach to the same idea arose from thestudy of terrestrial gravitation. As soon as gravity wasregarded no longer as a factor residing in the heavy bodyitself, as Aristotle taught, but as an interaction between anactive principle, extraneous to the gravitating body, and apassive principle, inherent in matter, as Alfonso Borelliand Giovanni Baliani (author of De Motu Gravium, 1638)contended, the notion of inertial mass became a necessityfor a dynamical explanation of free fall and other gravita-tional phenomena. Furthermore, Christian Huygens’s

investigations of centrifugal forces (De Vi Centrifuga,1659; published in Leiden, 1703) made it clear that aquantitative determination of such forces is possible onlyif with each body is associated a certain characteristicproperty proportional to, but conceptually differentfrom, the body’s weight. Finally, the systematic study ofimpact phenomena, carried out by John Wallis, SirChristopher Wren, and Huygens, enforced the introduc-tion of inertial mass. With Newton’s foundations ofdynamics (Principia, 1687) these four categories ofapparently disparate phenomena (planetary motion, freefall, centrifugal force, and impact phenomena) foundtheir logical unification, through his consistent employ-ment of the notion of inertial mass. Newton’s explicit def-inition of this concept, however, as “the measure ofquantity of matter, arising from its density and bulk con-jointly” was still unsatisfactory from both the logical andthe methodological points of view. It was probably theinfluence of Kepler or of Robert Boyle and his famousexperiments on the compressibility of air that made New-ton choose the notion of density as a primary concept inhis peculiar formulation of the definition of mass, a for-mulation that was severely criticized in modern times,especially by Ernst Mach and Paul Volkmann.

leibniz and kant

Gottfried Wilhelm Leibniz’s original conception of mass(1669), in contrast to Newton’s, defined it as that prop-erty which endows primary matter with spatial extensionand antitypy, or impenetrability. In his later writings,especially in his doctrine of monads, Leibniz associatedmass with secondary matter and saw in it a property of acollection of substances (monads) resulting from theirbeing a collection. Finally, recognizing the insufficiency ofpurely geometric conceptions to account for the physicalbehavior of interacting bodies, Leibniz departed from theCartesian approach and accepted the dynamic, or inertial,conception of mass. The trend of Leibniz’s ideas wasbrought to its final consequences by Immanuel Kant,with his rejection of the Newtonian vis inertiae, thedynamic opposition against impressed force. Refuting itslegitimacy on the ground that “only motion, but not rest,can oppose motion,” Kant postulated the law of inertia ascorresponding to the category of causality (“every changeof the state of motion has an external cause”) and conse-quently defined mass as the amount of the mobile (dieMenge des Beweglichen) in a given volume, measured bythe quantity of motion (Die metaphysischen Anfangs-gründe der Naturwissenschaft, 1786).

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definition of mass

Under the influence of the Kantian formulation, oftenincompletely understood, and primarily owing to the factthat in spite of the universal use of the concept in scienceas well as in philosophy no clear-cut definition of masswas available, most authors defined mass as quantity ofmatter without specifying how to measure it. Toward themiddle of the nineteenth century, with the rise of modernfoundational research and the critical study of the princi-ples of mechanics, the logical deficiency of such defini-tions became obvious. It was primarily Ernst Mach,preceded by Barré de Saint-Venant and Jules Andrade,who insisted on the necessity of a clear operational defi-nition of mass. In an essay, “Über die Definition derMasse” (1867; published in 1868 in Carl’s Repertorium derExperimentalphysik, Vol. 4, pp. 355–359), and in the Sci-ence of Mechanics (Die Mechanik in ihrer Entwicklung, his-torisch-kritisch dargestellt, Leipzig, 1883; translated by T. J.McCormack, La Salle, IL, 1942), Mach defined the ratio ofthe masses of two bodies that interact with each other butare otherwise unaffected by all other bodies in the uni-verse as the inverse ratio of their respective accelerations(m1/m2 = a2/a1), thereby converting Newton’s third law ofaction and reaction to a definition of mass. If a particularbody is chosen as the standard unit of mass, the mass ofany other body can be unambiguously determined bysimple physical operations. The practical method of com-paring masses by weighing is, of course, operationally stillsimpler but logically more complicated, since the notionof weight presupposes that of mass. Although Mach’s def-inition is not quite unobjectionable, it has gained greatpopularity and is generally adopted in modern texts inscience.

inertial and gravitational mass

In addition to its inertial mass, every physical body pos-sesses gravitational mass, which determines, in its activeaspect, the strength of the gravitational field produced bythe body and, in its passive aspect, the amount by whichthe body is affected by the gravitational field produced byother bodies. According to Newton’s law of universalgravitation, the force of attraction is proportional to theinertial masses of both the attracting and the attractedbodies. The resulting proportionality of inertial and grav-itational masses of one and the same body, experimen-tally confirmed by Newton, Friedrich Bessel, Roland vonEötvös, and others, remained in classical physics a purelyempirical and accidental feature, whereas the strict pro-portionality between the active and the passive gravita-tional masses is a straightforward consequence of

Newton’s third law of action and reaction or, alterna-tively, of the very definition of inertial mass if the postu-lated interaction is of gravitational nature. In generalrelativity, however, the so-called principle of equivalence,which maintains the unrestricted equivalence betweenuniformly accelerated reference systems and homoge-neous gravitational fields, implies the fundamental iden-tity between inertial and passive gravitational masses. Inaddition, it can be shown that on the basis of general rel-ativity the active gravitational mass of a body or dynam-ical system equals its inertial mass, so that in relativisticphysics, in contrast to Newtonian physics, the identity ofall three kinds of masses is a necessary consequence of itsfundamental assumptions.

mass and energy

Whereas general relativity led to an important unificationof the concept of mass, special relativity already, withAlbert Einstein’s paper Does the Inertia of a Body Dependupon Its Energy Content? (1905; reprinted in The Principleof Relativity, New York, 1923), led to a vast generalizationof the concept by showing the equivalence of mass andenergy insofar as a body emitting radiative energy of anamount E loses mass to an amount of E/c2, where c is thevelocity of light. Subsequent research, especially in con-nection with energy transformations in nuclear physics,supported the general validity of the formula E = mc2,according to which mass and energy are interconvertibleand one gram of mass yields 9¥1020 ergs of energy. It alsobecame obvious that Antoine Lavoisier’s law of the con-servation of mass (1789) and Robert Mayer’s (or Her-mann Helmholtz’s) law of the conservation of energywere only approximately correct and that it was the sumtotal of mass and energy that was conserved in anyphysicochemical process.

influence of the

electromagnetic concept

The way to these far-reaching conclusions of relativityhad been prepared to some extent already by the intro-duction of the electromagnetic concept of mass at theend of the nineteenth century (by J. J. Thomson, OliverHeaviside, and Max Abraham). It seemed possible on thebasis of James Clerk Maxwell’s electromagnetic theory toaccount for the inertial behavior of moving charged par-ticles in terms of induction effects of purely electromag-netic nature. Walter Kaufmann’s experiments (1902) onthe deflection of electrons by simultaneous electric andmagnetic fields and his determination of the slightly vari-able inertial mass of the electron seemed at the time to

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support the hypothesis that the mass of the electron, andultimately the mass of every elementary particle, is ofpurely electromagnetic nature. Although such eminenttheoreticians as H. A. Lorentz, Wilhelm Wien, and HenriPoincaré accepted these ideas, according to which thewhole universe of physics is but an interplay of convec-tion currents and their radiation, with physical realitystripped of all material substantiality, the electromagneticconception of mass had to make way for the relativisticconcept as outlined above. Certain aspects of the electro-magnetic conception of mass did survive, however, andreappeared in modern field theories—in particular thefundamental tenet that matter does not do what it doesbecause it is what it is, but it is what it is because it doeswhat it does.

See also Aristotle; Boyle, Robert; Energy; Ibn Gabirol,Solomon ben Judah; Kant, Immanuel; Kepler,Johannes; Leibniz, Gottfried Wilhelm; Mach, Ernst;Maxwell, James Clerk; Neoplatonism; Newton, Isaac;Patristic Philosophy; Philo Judaeus; Plotinus; Poincaré,Jules Henri; Proclus; Thomas Aquinas, St.

B i b l i o g r a p h yBainbridge, K. T. “The Equivalence of Mass and Energy.”

Physical Review 44 (1933): 123.

Comstock, D. F. “The Relation of Mass to Energy.”Philosophical Magazine 15 (1908): 1–21.

Jammer, Max. Concepts of Mass in Classical and ModernPhysics. Cambridge, MA: Harvard University Press, 1961;Mineola, NY: Dover, 1997.

Lampa, A. “Eine Ableitung des Massenbegriffs.” Lotos 59(1911): 303–312.

Mach, Ernst. Die Geschichte und die Wurzel des Satzes von derErhaltung der Arbeit. Prague, 1872.

Pendse, C. G. “On Mass and Force in Newtonian Mechanics.”Philosophical Magazine 29 (1940): 477–484.

Whittaker, E. T. “On Gauss’ Theorem and the Concept of Massin General Relativity.” Proceedings of the Royal Society, A, 149(1935): 384–395.

M. Jammer (1967)

materialism

Materialism is the name given to a family of doctrinesconcerning the nature of the world that give to matter aprimary position and accord to mind (or spirit) a sec-ondary, dependent reality or even none at all. Extremematerialism asserts that the real world is spatiotemporaland consists of material things and nothing else, with twoimportant qualifications: first, space and time, or space-

time, must also be included if these are realities ratherthan mere systems of relations, for they are not materialthings in any straightforward sense. Second, materialismis fundamentally a doctrine concerning the character ofthe concrete natural world we inhabit, and it is probablybest to set to one side controversies over abstract entitiessuch as numbers, or geometric figures, or the relations ofentailment and contradiction studied in logic. A strictlyextreme materialism would undertake to show that, tothe extent that any of these were genuine realities, theyare all material in nature, but the issues raised by abstractentities will not be pursued here. It is with extreme mate-rialist views in the concrete realm that this entry is con-cerned, and in what follows, “materialist” is to beunderstood in that sense.

Philosophers and scientists have had various viewsregarding the constitution and behavior of materialobjects and over whether every material thing is a body,or whether forces, or waves, or fields of force are also real-ities in their own right. Thus, the cardinal tenet of mate-rialism, “Everything that is, is material,” covers a range ofdifferent claims.

To accommodate these differences, a material thingcan be defined as a being possessing many physical prop-erties and no other properties, or as being made up ofparts all of whose properties are physical. The physicalproperties are position in space and time, size, shape,duration, mass, velocity, solidity, inertia, electric charge,spin, rigidity, temperature, hardness, magnetic fieldintensity, and the like. The phrase “and the like” is impor-tant, for it indicates that any list of physical properties isopen-ended. A material thing is one composed of prop-erties that are the object of the science of physics. Andphysics is a developing science, in which new propertiesare still being discovered. The question “What counts as aphysical property?” thus has no determinate answer. Inconsequence, there are also no fully determinate answersfor the questions “What is a material thing?” and “Whatdoes materialism claim?”

This is less serious for materialism than may at firstappear, for there is a broad consensus on which proper-ties—among those already known—are the physicalones. And new properties that emerge from research inthe physical sciences are, generally speaking, readily iden-tified as belonging among the physical ones rather thanrepresenting an anomalous, nonphysical development. Itis known well enough what is involved in claiming thatsomething is a material reality, and therefore it is under-stood well enough what is involved in the various ver-

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sions of extreme materialism, all of which assert thateverything there is, is material.

The psychological characteristics people ascribe tothemselves and to one another—consciousness, purpo-siveness, aspiration, desire, and the ability to perceive, forexample—are not considered to be physical properties.So materialism differs from panpsychism, the doctrinethat everything material is also at least partly mental orspiritual. Materialism denies the world’s basic entitiespossess these psychological properties. Materialists addthat there is no second class of nonmaterial beings in pos-session of such psychological properties and no others;there are no incorporeal souls or spirits, no spiritual prin-cipalities or powers, no angels or devils, no demiurgesand no gods (if these are conceived as immaterial enti-ties). Hence, nothing that happens can be attributed tothe action of such beings.

The second major tenet of materialism is, accord-ingly, “Everything that can be explained can be explainedon the basis of laws involving only the relevant physicalconditions.” The differences among materialists over thetypes of effect material things can have on one anothermake this second tenet another slogan covering a varietyof particular doctrines. Further, although materialistshave traditionally been determinists, holding that there isa physical cause for everything that happens, this is notstrictly required by materialism itself. Recently, the appealof determinism has been weakened by the developmentand success of quantum theory, and many contemporarymaterialists are not committed to determinism. It shouldalso be mentioned that metaphysical materialism in noway involves an overzealous disposition to pursue moneyand tangible goods, despite the popular use of “material-istic” to describe this interest.

nature and appeal of

materialism

The enduring appeal of materialism arises from itsalliance with those sciences that have contributed most toan understanding of the world humans inhabit. Investi-gations in the physical sciences have a materialistmethodology; that is, they attempt to explain a class ofphenomena by appeal to physical conditions alone. Theclaim of materialists is that there is no subject matter thatcannot be adequately treated with a materialist method-ology. This claim cannot be established by any scientificinvestigation; it can be established, if at all, only by criti-cal reflection on the whole range of human thought andexperience.

Early philosophers proceeded dogmatically, aiming

to prove the material nature of the world by mere reflec-

tion on what must be. Contemporary materialists are

much more modest, offering the claim as a speculative

but reasonable generalization from the progress of the

physical sciences.

Materialism has been, traditionally, a minority view,

indeed a rather daring and scandalous one, but it has

made considerable progress over the past century, partic-

ularly among educated European peoples. There seem to

be three main reasons for this. First, the rise of what

might be called “cosmic naturalism”; there has been a

decline in those aspects of religious conviction that

involve appeal to providential or satanic interventions in

the course of events, so that pestilence or climate change,

for example, are not attributed to nonmaterial, supernat-

ural forces. Second, the rise of “medical materialism”; the

discovery of the biochemical mechanisms involved in

neural functioning, and their links to psychological

processes, so that it is now taken for granted that think-

ing, feeling, and the will are subserved by the nervous sys-

tem, and can be altered by making physical changes by the

use of drugs or electrodes. A malfunction of the mind is

taken to be a malfunction of the brain. This is a kind of

pragmatic materialism—the physical aspects are

accorded primacy. Third, the rise of “electronic material-

ism”; recent years have witnessed an astonishing expan-

sion in the range and sophistication of the mental tasks

that digital machines can perform. Not only remember-

ing, recalling, and calculating, but pattern recognition,

estimation processes, problem solving, and learning new

skills, which hitherto have been the exclusive preserve of

living, conscious beings, are now routinely performed by

electronic devices that, unless panpsychism is true, are

purely physical structures. This has formed the back-

ground for an increasingly common assumption that

mental activity is a special kind of physical process, which

is one critical aspect of materialism.

Materialism remains, nonetheless, a striking and

apparently paradoxical doctrine, for it insists that the

only differences between human beings and grains of

sand prove to be matters of energy flow and structural

complexity. People have continued to embrace material-

ism in the face of the difficulties with which it is beset

because it offers a comprehensive, unified account of the

nature of reality that is economical, intelligible, and con-

sistent with the most successful of the sciences.

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history of materialism

CLASSICAL PERIOD. Materialism has been a theme inEuropean speculative thought from the earliest periodsfor which there is any record.

Ionian philosophers in the tradition of Thales (sixthcentury BCE) attempted to account for the origin andpresent state of the world by appeal to changes in the stateof a fundamental underlying substance (the arche), whichin most cases was held to be of a physical nature. Par-menides of Elea (fifth century BCE) vigorously defendeda thoroughgoing monism, maintaining that the world isOne, unchanging, eternal, homogeneous, indivisible,indestructible, and without any interior void.

These two threads of thought are combined in thetrue materialism of Leucippus and his pupil Democritus,who flourished at Abdera in the fifth century BCE.Between them they worked out the first clear conceptionof matter, the first clear restrictions on the kinds of natu-ral interactions in which material particles could partici-pate, and the first clear program of explanation by appealto these material interactions alone. The “Great Diakos-mos,” a lost work written by one or the other (or both),expounded their position. Their basic idea was that thefundamental stuff was of just one kind (matter) and thatthe fundamental entities were material atoms that were ofcourse by no means unique, but otherwise had all thecharacteristics of Parmenides’ One. These atoms are inconstant motion in a void that surrounds them.

Insofar as it can be reconstructed, their doctrineembraced the following theses:

(1) Nothing exists but atoms and empty space.

(2) Nothing happens by chance (for no reason at all);everything occurs for a reason and of necessity.This necessity is natural and mechanical; itexcludes teleological necessitation.

(3) Nothing can arise out of nothing; nothing that iscan be destroyed. All novelties are merely newcombinations or separations of atoms.

(4) The atoms are infinite in number and endlesslyvaried in form, but uniform in composition,being made of the same stuff. They act on oneanother by pressure or collision only.

(5) The great variety of things that we encounter inthe world is a consequence of the variety in num-ber, size, shape, and arrangement of the atomsthat compose them.

(6) The atoms have been in confused random motionfrom all eternity. This is their natural state and

requires no explanation. (Some scholars disputethe attribution of random motion to the atomsand credit the “Great Diakosmos” with advancingthe doctrine of an eternal fall through infinitespace, which was later presented by Epicurus.)

(7) The basic mechanism whereby complex bodiesare formed is the collision of two atoms, settingup a vortex. In the vortex motion is communi-cated from the periphery toward the center. Inconsequence, heavy atoms move to the center, andthere form a body, which is dense relative to thecollection of light atoms around the periphery.The vortex continually embraces any new atomsthat come near it in their random motion, and itthus begins a world.

This materialist philosophy requires a mechanicalaccount of human sensation. The Leucippus-Democritusaccount seems to have been ingenious, speculative, andfalse. Sensation occurs in the human soul, which, likeeverything else, is composed of atoms. Objects percepti-ble by the distal senses sight, hearing, or smell, give offeffluences, or images, composed of fine, smooth atoms.There are channels in the eyes, ears, and nose along whichthese effluent atoms pass to collide with the atoms of thesoul and produce sensation. Differences of color, in thecase of vision, or of pitch, in the case of sound, are due tothe varying smoothness or roughness of the incomingimage atoms. With the contact senses touch and taste, it isthe size and shape of the atoms on the surface of the per-ceived object that act on soul atoms in the skin or tongue.

Sensory qualities (for example, sweetness, bitterness,temperature, and color) are thus not qualities of theobject perceived, which is a collection of atoms, possessedonly of physical properties such as size, shape, mass, andhardness. The sensory qualities are, rather, the effects ofthat collection of atoms on us, that is, on our soul atoms.Here is an early appearance of the distinction betweenprimary and secondary qualities, a distinction every sub-sequent materialist has also found it necessary to make.

Empedocles (fifth century BCE) founded a medicalschool in Acragas (Agrigento) in Sicily. His aim was toaccount in a naturalistic manner for the special featuresof this world, particularly for the specially organized mat-ter to be found in living creatures. The first appearance ofthe famous four elements—earth, air, fire, and water—isin his theory. Empedocles seems to have believed thateach of these four elements comprised a different type ofatom. The creation and dissolution of the macroscopicobjects of this world is brought about by the combination

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and separation of these atoms by two fundamental forces,love and hate, or harmony and discord.

Under the influence of love and hate the world goesthrough an endless cycle from complete random separa-tion of elements (the triumph of hate), through graduallyincreasing order, to a complete, calm, spherical, harmo-nious union (the triumph of love). Hate then begins toexert itself once more. Disintegration sets in, and ulti-mately the world returns to the state of complete separa-tion of elements. The present state of the world liesbetween these two extremes. The existence of planetarysystems and the origin of animals are thus explained asthe influence of love.

Empedocles can be considered a true materialist onlyif love and hate are either inherent forces in the elemen-tal atoms or themselves material elements with a cement-ing or corrosive effect on combinations of the otherelements; however, he probably thought of them as blind,powerful gods. The rest of his system is similarly ambigu-ous. On the one hand, he believed in the transmigrationof souls and adhered to some kind of Orphic mysteryreligion; on the other, he gave a mechanical account ofsensation, held that the soul was composed of fieryatoms, and said that the blood around the heart is thethought of men. Empedocles’ philosophy thus perpetu-ated the materialist tradition but not in a rigorous or con-sistent form.

The hostile misinterpretation of his ethics asunworthily hedonistic has made Epicurus (342–270 BCE)the most famous of classical materialists. In his middleage Epicurus came to Athens and founded a school wherematerialism was taught as the sole foundation of a goodlife, at once disciplined, calm, serene, and free fromsuperstition.

He adopted the materialist metaphysics of the “GreatDiakosmos” but gave a modified account of the origin ofworlds. There are an infinite number of atoms falling ver-tically through an infinite space. In one construction ofthe Epicurean system the heavier, faster atoms occasion-ally strike the lighter, slower ones obliquely, giving them aslight lateral velocity. In another construction all atomsfall at uniform velocity, and the original deviations fromparallel downward motion are left unexplained.

However caused, the original lateral deviations resultin more collisions and deviations and the establishmentof vortexes. From these vortexes ordered arrangements ofatoms arise. The number of atoms and the time availableare unlimited, so every possible arrangement of atomsmust occur at some time or another. This world, with its

marvelously organized living bodies, is thus just one ofthe infinite, inevitable arrangements into which the inde-structible atoms must fall.

The only Roman author of note in the tradition ofmaterialism is Lucretius (born c. 99 BCE), whose longdidactic poem De Rerum Natura gives imaginativesparkle to the metaphysics of Epicurus. Lucretius adoptedthe second account of the fall of atoms through the voidand appealed to some form of voluntary action to explainthe original deviations from vertical descent. He thusintroduced a nonmechanical source of motion, inconsis-tent with the remainder of his system.

Like Epicurus, Lucretius was motivated by a wish tofree people from the burden of religious fear. He arguedpassionately and at length against the existence of anyspiritual soul and for the mortality of humankind. Thesebeliefs have been explicit features of materialism eversince.

SEVENTEENTH CENTURY. From the close of the classi-cal period until the Renaissance the church and Aristotleso dominated European speculation that materialist the-ories virtually lapsed. The revival of materialism is attrib-utable to the work of two seventeenth-centuryphilosophers, Gassendi and Hobbes, who crystallized thenaturalistic and skeptical movements of thought thataccompanied the rediscovery of antiquity and the rise ofnatural science. Their most important forerunners wereprobably Telesio, Campanella, and Cyrano de Bergerac,all of whom attempted to combine materialistic views inphysics with a psychology based on sensations.

Pierre Gassendi (1592–1655), who in the last part ofhis life taught astronomy at the Royal College in Paris,rejected the official Aristotelian philosophy of his timeand set about the rehabilitation of Epicureanism. Tobring the Epicurean system into closer conformity withChristian doctrine, he claimed that the atoms are noteternal but created. They are finite, not infinite, in num-ber and are organized in our particular world by a provi-dential determination of initial conditions.

Gassendi’s materialism extended over physics andpsychology, undertaking to account for all inanimatechanges and for sensation on a materialist basis. Hetreated the coming into being of particular things as theaccumulation of matter about a seed atom.

But his metaphysics was not, strictly speaking, mate-rialistic, for outside the experienced world Gassendiadmitted a creative and providential God and an imma-terial and immortal intellect in man distinct from his cor-poreal soul. There are even some lapses in the physics,

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too, for Gassendi spoke of gravitation as some kind ofmovement for self-preservation and allowed that growthfrom seed atoms may be controlled by formative princi-ples other than the natural motions of atoms.

Thomas Hobbes (1588–1679) was much more con-sistent and uncompromising. In 1629 he discoveredEuclidean geometry and was captivated by its method.During the years that followed he strove to work out arational philosophy of nature on the Euclidean model.

Hobbes’s aim was to discover by cunning analysis ofexperience the fundamental principles expressing thetrue nature of everything. The truth of these principleswould be manifest to right reason and could thus serve asaxioms from which a comprehensive theory of the natureof the world could be deductively derived.

The resulting system is almost pure materialism.Hobbes hoped to use the new non-Aristotelian physics ofthe seventeenth century as the basis for a final, completeaccount of reality. From definitions of space and motionhe derived the laws of uniform motion. From these,together with a notion of the interaction of bodies, hehoped to proceed to an account of change, thence to anaccount of sensible change, thence to a theory of thesenses and appetites of people, and finally to his notori-ous civil philosophy.

No part of the universe is not a body, said Hobbes,and no part of the universe contains no body. Hobbes wasa plenist, holding all space to be filled by an intangiblematerial ether if nothing else. This doctrine followeddirectly from his definition of a body as anything existingindependently of human thought and having volume.Thus, Hobbes considered God to be a corporeal spirit dif-ficult to distinguish from his eternal, immutable,omnipresent, embodied space, the pervasive ether.

All change in the universe consists in the motion ofbodies, so all change reduces to change of position andvelocity. Further, nothing can cause a motion but contactwith another moving body. The substance of anything isbody, and “incorporeal substance” is therefore a contra-diction in terms. Hobbes thereby disposed of angels, thesoul, and the God of orthodox theology. He departedfrom strict materialism, however, in his introduction of“conatus” and “impetus” (which are not physical proper-ties) into his account of the initiation of motion andmeasurement of acceleration. Conatus also enters intoHobbes’s account of human sensation and action. Sensa-tions are motions in a person’s body, and changes of sen-sation are changes of that motion. Sensory qualities are

really within the perceiver, but by conatus a “phantasm” isprojected from the observer onto the observed.

Hobbes was the first to take seriously the problemsthat language, thought, and logic pose for materialism.He developed a nominalist theory of language and tookthe subject matter of thought and inference to be phan-tasms of sense or abstractions from these phantasms. Heheld, for example, that to remember is to perceive one hasperceived. But Hobbes did not make clear just what con-tact mechanism is at work in mental operations norwhether the phantasms are genuinely corporeal. Thus, inspite of his best efforts, it is doubtful that he developed afully consistent materialism.

The influence of Gassendi and Hobbes was dimin-ished by the prestige of their brilliant contemporary, ReneDescartes (1596–1650), who accepted a materialist andmechanical account of the inanimate world and the brutecreation but insisted that men had immaterial, im-mortal spirits whose essential nature lay in conscious thought undetermined by causal processes. According toDescartes, there are in the world two quite different sortsof things, extended (material) substances and thinking(spiritual) substances, which are mysteriously united inthe case of humankind. He thus crystallized the traditionof dualism (the doctrine that there are just two funda-mentally different kinds of substance), which was untilrecently materialism’s chief rival.

EIGHTEENTH CENTURY. In Epicurus and Lucretiusone motive for working out a materialist philosophy was to provide an antidote for the all too prevalent reli-gious terror of their times. With Hobbes, and again in eighteenth-century France, the corresponding motivewas opposition to religious oppression. But in addition,rapid growth in physiological knowledge had given rise tothe hope that a complete doctrine of man in purely phys-iological terms was possible and so generated a medicalmaterialism that made the path of the metaphysicianssmoother.

Ever since the time of Democritus, materialists hadheld that the soul consists of fine particles within thebody. In the course of the eighteenth century this sugges-tion was taken up and amplified, and some attempt wasmade to give it an experiential basis.

An anonymous manuscript, the Ame materielle, writ-ten between 1692 and 1704, contains many ingeniousexplanations of mental function along Democriteanlines. Pleasure and pain consist, respectively, of the flowof finer or coarser particles through the channels of thebrain. The passions are a matter of the temperature of the

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heart. Reason consists in the ordering of the soul’s fineparticles, and the effect of wine in its course through thebody is to dislodge some of these fine particles from theirproper places. The manuscript is panpsychic in its expres-sion, crediting the atoms with a rudimentary conscious-ness and will, but it is materialist in substance, for thesequalities are not credited with any causal power. The doc-trines advanced were purely hypothetical and, as we nowknow, false. The Ame materielle had successors in Dr.Maubec’s Principes physiques de la raison et les passions del’homme (1709), which again gave a materialist vision ofman a panpsychic dress and opposed Descartes’s view ofthe mind as a thinking substance. During the middleyears of the century, Denis Diderot’s many unsystematicwritings took progressively a more materialistic turn.Diderot’s Le reve de d’Alembert is a striking hypotheticalaccount of heredity, growth, and the simpler forms ofanimal behavior in terms of internal motions of livingbodies.

The most famous medical materialist is Jean de laMettrie (1709–1751), a doctor with a philosophical bentwhose radical views obliged him to leave a fashionablepractice in Paris to live in Holland and Prussia. InL’homme machine (1943 [1748]) he presented a view ofthe human being as a self-moving machine.

After criticizing all views of the soul as a spiritualentity, La Mettrie proceeded to review all the common-sense evidence for the physical nature of mental activity.He cited the effects of bodily needs, aging, and sleep; hepointed to the analogy of the human body to much“lower” forms, which were not supposed to harbor spiri-tual minds. Anticipating Pavlov, he spoke of the mechan-ical basis of speech and of the possibilities of educatingdeaf-mutes and anthropoid apes. He explained learningto perceive and learning to make moral judgments byappeal to modifications of the brain. Human action isaccounted for by the then new doctrine of the stimulusirritability of muscles. La Mettrie embarrassed those whoheld that the soul is a spiritual unity governing all vitalfunctions by observing the continuing function of organsremoved from bodies, the muscular activity of dead ordecapitated animals, and the ability of a bisected polyp togrow into two complete ones. He explained conscioussensation and the mental capacities of which we areintrospectively aware by means of a magic-lantern anal-ogy, but this was unsatisfactory, for the status of theimages involved was not made clear.

The details of La Mettrie’s physiology, depending asthey do on supposed movements of nervous filaments,are false. However, his program of seeking in neural

changes the explanation of mental activity has endured,and his claim that appeals to the actions of a spiritual soulcan furnish only pseudo-explanations has gained widesupport.

Jean Cabanis (1757–1808), a French doctor, contin-ued this line of thought and in 1802 published Rapportsdu physique et du moral de l’homme, the most notableinnovation of which was to treat the brain as analogouswith the digestive system, making sensory impressions itsaliments and thoughts its product. The great metaphysi-cal materialist of the period is Paul Heinrich Dietrichd’Holbach (1723–1789), a German nobleman living inParis. His work the Systeme de la nature was publishedunder a false name “Mirabaud,” with a false imprint“London” (Amsterdam) in 1770. This “Bible of all mate-rialism” is speculative philosophy in the grand style; in itthe antireligious motive is again uppermost. Holbachmaintained that nothing is outside nature. Nature is anuninterrupted and causally determined succession ofarrangements of matter in motion. Matter has alwaysexisted and always been in motion, and different worldsare formed from different distributions of matter andmotion. Matter is of four basic types (earth, air, fire, andwater), and changes in their proportions are responsiblefor all changes other than the spatiotemporal ones thatmotion without redistribution can accomplish.

Mechanical causes of the impact type, such as colli-sion or compression, are the only intelligible ones, hencethe only real ones. Because human beings are in natureand part of nature, all human actions spring from natu-ral causes. The intellectual faculties, thoughts, passions,and will can all be identified with motions hidden withinthe body. In action outward motions of the limbs areacquired from these internal movements in ways we donot yet understand.

Holbach based the intellectual faculties on feelingand treated feelings as a consequence of certain arrange-ments of matter. Introspected changes are all changes inour internal material state. Thus, in remembering, werenew in ourselves a previous modification. He treatedpersonal characteristics and temperament in terms of aperson’s internal structure and interpreted so-called freeaction not as motiveless action (an absurdity) but asaction that, although seeming to flow from a free choice,actually springs from an ultimately unchosen modifica-tion of the brain. Holbach’s theory of mind is also inter-esting because in dealing with wit and genius, it suggeststhe first behavioral analyses of mental concepts. As con-sistency required, he held the soul to be mortal. Thepurity of Holbach’s materialism is marred only by his

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admission of relations of sympathy, antipathy, and affin-ity among material particles, in addition to theirunequivocally physical properties, the primary qualities,gravity, and inert force.

The revolution in chemistry that was effected byJoseph Priestley (1777) in England and Antoine-LaurentLavoisier in France in the 1770s and 1780s was of impor-tance for the later development of materialism, for itestablished chemistry as a strictly physical science. Sincethe beginning of the nineteenth century, all properlychemical explanations appeal only to material substancesand their natural interactions. Such a chemistry has sincebeen extended in biochemistry to cover all the processesof life, and the case for materialism has thereby been pro-foundly strengthened. Priestley himself nevertheless vig-orously upheld an unorthodox version of Christianity,insisting that the existence of God and the resurrection ofthe body are not incompatible with a materialist anddeterminist view of the natural world.

NINETEENTH CENTURY. The philosophers of greatestinfluence in the nineteenth century—Kant, Fichte, Hegel,Schopenhauer, Lotze, and Mill, for example—were all ofan idealist or phenomenalist bent. The dialectical materi-alism of Friedrich Engels and Karl Marx is not an extremematerialism of the kind discussed here.

Ludwig Buchner, a minor figure, deserves mention asthe first to claim explicitly that materialism is a general-ization from a posteriori discoveries. In Kraft und Stoff(1855) he claims that we have discovered (not proven apriori) that there is no force without matter and no mat-ter without force.

There was during this period a continuation ofinquiry and speculation on the physiological bases ofmental function. Jacob Molescott (1852), Karl Vogt(1846, 1854), and Emil Du Bois-Raymond proceededwith the investigation of physiological processes alongbiophysical and biochemical lines. The most importantdevelopments were scientific findings that underminedthe barrier between physical systems and living organ-isms and thus softened the natural resistances to materi-alistic theses.

In 1828 the synthesis of urea was achieved, and thisrefuted the idea that biochemistry was in some way spe-cial and distinct from chemistry. In 1847, HermannHelmholtz established the conservation of energy inorganic systems, making still less plausible any claims thatliving and nonliving systems could not possibly be com-prehended in a single theory.

In 1859 Charles Darwin published his Origin ofSpecies, in 1871 his Descent of Man. T. H. Huxley had pro-duced Man’s Place in Nature in 1863. These three works atlast provided a plausible, empirically grounded case fortwo of the main planks of materialism, the claim that theorganization of living things into forms admirablyadapted for survival and reproduction can be explainedwithout appeal to immanent or transcendent purposes,and the claim that humans are a part and product of thenatural world. Since then biologists, physiologists, andpathologists have increasingly taken the truth of medicalmaterialism for granted, couching their explanations inphysicochemical terms without questioning the proprietyor completeness of successful explanations in this form.

TWENTIETH CENTURY. The triumphant progress inthe twentieth century of a materialistic biology and bio-chemistry has almost completely eliminated vitalistnotions of living forms as governed by forces additionalto, and distinct from, the purely physical forces operatingon inanimate matter. The situation of earlier ages hasbeen reversed; it now seems implausible to maintain thatthe vital functions of living organisms are different inkind from chemical (ultimately, physical) processes. Inthe attempt to demonstrate that something other thanmatter exists, it is on mind, rather than life, that theopponents of materialism now rely.

Early in the twentieth century, the behaviorist move-ment arose, in a development linked to the emergence ofpsychology as a distinct science in its own right, ratherthan a branch of the philosophy of mind. Many psychol-ogists became disheartened by the difficulties involved inany introspective investigation of inner mental states, andturned to the study of behavior. In its analyses and expla-nations of human activities, behaviorist psychology reliesas far as possible on publicly observable, physical phe-nomena of stimulus and response. Its aim was to expelthe traditionally conceived inner, immaterial mind frompsychology, and in this way was a profoundly materialis-tic development.

In the realm of the mind, a new challenge for imma-terialists has also developed. The rise of cybernetics (theabstract theory of machines) and its applications in com-puting machinery threatens the idea of a special status formental activity. The gathering and interpretation ofinformation, the employment of stored information, suc-cessful and spectacular problem solving, even analoguesof fatigue, overload, and confusion, hitherto all foundonly among complex living organisms, are now displayedby computing hardware, that is, by material structures all

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of whose operations can be explained in terms of physi-cal properties alone.

Approaching the issue from the opposite direction,experimental study of the nervous systems of animalsand of ourselves is showing, in ever-increasing detail, howartificially induced physical changes in the electrochemi-cal state of the nervous system issue in changes in thesubject’s mental activity. Displays of emotion, perform-ance in perception and recall, and anxiety and tension arebeing tied down to brain function in this way.

During the twentieth century, there were in fact threedistinct movements of a materialistic stamp in the phi-losophy of mind. In the 1920s and 1930s some logicalpositivists, led by Rudolph Carnap (1932–1933) and OttoNeurath, espoused an epistemic materialism. They heldthat the meaning of any statement consists in the directlytestable statements deducible from it (the protocol sen-tences). In order for language and meaning to be publicand shared, these protocol sentences must be intersubjec-tively testable. However, because no statement about oneindividual’s experience or thought or other inner psycho-logical state can be tested by anyone else, only sentencesreferring to the physical properties of physical entities areintersubjectively testable in the required way. Now,because most statements about minds are incontestablymeaningful, they must, despite appearances to the con-trary, in fact refer to physical properties and entities, eventhough translations of them into physical terms cannotbe provided. In this way the philosophy of language led toa behaviorist materialism.

The beginnings of translation into behavioral termswas offered for some psychological expressions—forexample, “is happy”—by directing attention to the way inwhich the use of such expressions is taught. A key elementin teaching such an expression is to point to peoplebehaving happily. In this emphasis on the conditionsunder which an expression can be learned, the positivistsanticipated the favorite strategy of Ludwig Wittgenstein(1953) and moved away from complete dependence ontheir general doctrines of meaning and verification.

During the middle years of the twentieth century, theanalytic behaviorists, in particular Gilbert Ryle (1949)and his followers, offered to show that descriptions ofstates of mind are essentially dispositional, so that attri-butions of intention and intelligence, choice and desire,excitement and fear, and other mental states are all to beunderstood as attributions of a disposition to behave in acharacteristic manner in appropriate circumstances. Dis-positions are held by most thinkers to issue from somestanding or recurrent underlying state, and with these

analytic behaviorists the relevant states underlyinghuman mental life were assumed to be states of the body.Their manifest intention to exorcise any spiritual soul—as Ryle would put it, any “ghost in the machine”—placesthem in the materialist tradition.

Wittgenstein, although he disdained the title behav-iorist, belongs to the same group. He insisted that in anyacceptable analysis of a mental concept the description ofa person’s state of mind must make reference only to pub-licly detectable features of the organism and its behavior.His many subtle discussions of mental concepts are allattempts to identify the patterns of behavior whose dis-play would constitute being in a given state of mind. Toattribute that state of mind to someone is to attribute adisposition to display the relevant pattern of behavior.The alternative analysis that interprets the various statesof mind as states and processes in a spiritual soul is,according to Wittgenstein, not merely false, it is unintelli-gible.

On two key points the analytic behaviorists were notconvincing. First, if mental states are dispositions to dis-play particular patterns of behavior, they cannot becauses of the behavior in question. It cannot be that aman’s anger made him shout, for the shouting is itself justan aspect of the anger. Nor can a woman’s pride havemade her stubborn. Yet this causal link between a mentalstate and the characteristic behavior pattern that springsfrom it, is at the heart of how we understand one another.

Second, some inner mental episodes, such as after-images, pains, sudden unsought recollections, dreams, orflashes of insight, resist any plausible dispositional analy-sis. The mind does seem to be a collection of categoricalstates, items, or events in addition to a cluster of disposi-tions. The effort to correct both these weaknesses, first thedenial of any categorical component, and later the denialof any causal power to the mind, was a significant factorin materialism’s subsequent development.

The third group of twentieth-century materialistsembraced a theory of mind known as central-state phys-icalism, from which contemporary materialism derives.The central-state physicalists held that although it may bethat some mental states can be understood disposition-ally, there are many mental states, items, or events thatmust be accorded a straightforwardly categorical status.These categorical mental states turn out to be, as a matterof contingent fact, states of the central nervous system. Tointrospective awareness they do not seem to be neuralstates, but the explanation for this is that the nervous sys-tem is presented to itself in an opaque or covert fashion.

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The mind has many aspects, and mental life under-pins almost every distinctively human capacity. Most ofour distinctive capacities have been pointed to as showingthat a living human being must be something more thana mere assemblage of atoms. To understand ourselves, wecannot do without the concepts of perception, belief, andintelligence; action, decision, and choice; motive, drive,and need; feeling, emotion, and mood; temperament andcharacter. We will also need to treat of consciousness andself-consciousness. The task for materialists is to explainhow merely material structures could exhibit all thesemental attributes. In attempting this, two basicapproaches were at first adopted, the behavioral and thetopic neutral.

Behavioral strategy. The central-state physicalistswere able to appropriate the earlier work of the behavior-ists and accept that the attribution to an organism ofsome of the mental predicates (for example intelligence,equanimity, or ambition) is in reality the attribution of adisposition to behave in a characteristic way under suit-able conditions. The organism displaying the behavior,the form the behavior takes, and the conditions underwhich it is manifested, are all specifiable in purely physi-cal terms. Moreover, the remarkable subtlety and com-plexity of human behavior, which until the twentiethcentury appeared to surpass anything of which a meremachine could be capable, no longer has such immateri-alist implications, for now the development of elec-tronic machines suggests that the ability to duplicate human performance is possible. In particular, the self-monitoring features of conscious behavior can be dis-played by material systems.

Topic-neutral strategy. Many mental states resist thebehavioral strategy: being in pain, seeing a color, or feel-ing depressed, for example. For these, a different claimwas made: To attribute such a state is to assert that thereis present within the organism some state or process thattypically arises from a particular kind of stimulus and/ortypically issues in a characteristic kind of behavior. Aburning pain, for example, is a state of a person typicallyarising from excessive heat on the skin, and characteristi-cally issuing in applications of soothing cream to theaffected part. Mental predicates of this kind have beencalled topic-neutral because they do not specify the natureof the inner state in question. The inner state is notdescribed either as material or as immaterial. To say thatsomeone is in pain, the argument runs, does not of itselfimply that the experience belongs to a immaterial mind.It implies only that the person is in some central state orother, arising from the states and processes in the sensory

system (input), and issuing in certain behavior patterns(output). When we attempt to identify this central state,we find that the sensory system provides inputs to theorganism’s central nervous system, which in turn sets intrain the muscular movements required for any type ofbehavior. If inner states admit of the topic-neutral treat-ment, they, too have no immaterialist implications.

Among early central-state physicalists, some, such asPaul K. Feyerabend (1963) and Hilary Putnam, claimedonly that this is the most promising line for investigationto now take. Others, such as U. T. Place (1956), J. J. C.Smart (1959, 1963), and Herbert Feigl (1958), went fur-ther and held that any alternative dualist view is alreadyfrankly incredible.

contemporary materialism

During the later years of the twentieth century, under theinfluence chiefly of David Armstrong (1968) and DavidLewis (1972), the topic-neutral strategy was taken up anddeveloped. The behavioral strategy became less promi-nent, as more and more mental attributions were inter-preted as asserting that the organism was in anappropriate categorical state. And the role of the mentalas the causal bridge between stimulus and response wastaken up and emphasized. Mental states came to beregarded as theoretical constructs and assimilated toother theoretical entities more familiar from other sci-ences, as philosophers adopted a third strategy foraccounting for mental descriptions in a material world.

CAUSAL/THEORETICAL STRATEGY. In a completedeparture from the behaviorist viewpoint, which sawmentality as a matter of the outer effects of stimuli, thenew position is that the really essential thing about anymental state is its causal role, as the crucial inner inter-mediary between input and response. The idea is that theactivity of conscious living beings calls for explanation,and the most appropriate explanations will attribute tosuch organisms inner states, produced by environmentaland remembered elements, and producing behavior that,in the light of the organism’s beliefs, is best suited to ful-filling its purposes.

So the mind becomes an inner, theoretical entity, thethat-which-best-accounts-for the phenomena of con-scious behavior. The analogy was drawn with the gene inbiology, that-which-best-accounts-for the phenomena ofheredity, and with lightning, that-which-best-accounts-for flashes, thunder, and some kinds of storm damage.

Then, still following the analogy, the research ques-tion becomes that of finding which element in the world

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turns out to fill the theoretical role in question. Structurescrucially involving the DNA molecule, as it turns out, bestaccount for heredity. Electrical discharges, as it turns out,best account for the flashes, rumbles, and damage of elec-trical storms. This is a matter of the contingent identifi-cation of underlying structures and processes as thecausal bases for patterns of observed phenomena. So withthe mind: It is the central nervous system (brain, opticnerve, spinal chord, and some other components) that, asit turns out, fulfills the mind’s causal role as the interme-diary and clearinghouse between the inputs, many ofwhich we know as experience, and the outputs that con-sist in purposive activity.

In this way functionalism, the dominant form ofcontemporary materialism, developed. It has two compo-nents. The first component is a theory of the mind, whichasserts that the essential feature of the mind is its causalrole, and identifies the different states of mind—beliefs,fears, plans, twinges, and so forth—in terms of their par-ticular places in the whole mental causal scheme. Thistheory of the nature of mind lends itself to materialism,but is not itself materialist. It is topic-neutral, allowing forany of a number of views of what it is that provides thecausal bridge between inputs and responses. The secondcomponent in functionalist materialism is the theoreticalidentification of the mind with the central nervous sys-tem. This is a contingent assertion about what minds turnout to be in this world. As such, it is vulnerable to variousempirical developments, as all substantial empiricalclaims should be.

objections to materialism

THE POSSIBILITY OF SCIENTIFIC REFUTATION.

Materialism is a strong version of naturalism. It assertsthat everything whatsoever that occurs in this world is theresult of the operation of physical forces in accord withphysical laws. So a spectacular and unequivocal divineintervention in the course of nature, such as the Apoca-lypse and the Day of Judgment as described in the bookof Revelation, would spell the end of materialism as acredible philosophy.

Less spectacular developments could have the sameimpact. The firm establishing of parapsychological pow-ers (telepathy, clairvoyance, or psychokinesis) would doso, for by definition any paranormal phenomenoninvolves knowledge or action by a mind in defiance ofphysical law. So also would developments in neural sci-ence that uncovered variations in effectual states of mindwithout any appropriate change in states of the centralnervous system. Or changes in the central nervous system

linked to changes in mental state, such as forming a newresolution, that systematically violate the probabilities forneural change that physical laws set forth and that defyany modification to accepted physical laws.

Materialism, being vulnerable in these ways, remainsto that extent speculative. But whereas a watching briefneeds to be kept over the progress of scientific investiga-tions, it is fair to say that there is at present no seriousthreat from these quarters. The credibility of positiveparanormal results has, if anything, diminished in thecourse of the past half century. And we are very far indeedfrom being able to assert that the activity of the brain isphysically anomalous. Quite the contrary; so far, noapparent violations of physical law have been found.

THEOLOGY. Materialism not only holds that there areno supernatural interventions in the course of nature, butthat there are no divine beings of any kind. To defendmaterialism on these points, one must first show thatthere is no valid deductive argument for the existence ofa necessary being, then sustain the view that this worlddoes not call for a divine creator as the best explanationfor its existence and character.

Next, one must deny that religious experience revealsa supernatural realm, as vision provides access to a phys-ical one. Adopting the skeptical empiricists’ critique, onecan argue that religious experience is not sufficiently uni-form, widespread, and unanimous to warrant abandon-ing the natural modes of explanation that have served sowell in all other enquiries, especially as supernaturalhypotheses face peculiar difficulties when it comes toputting them to the test. The materialist position isstrengthened by the promise of continued success in find-ing concrete natural explanations of religious experiencethrough developments in sociology, psychology andphysiology.

If these positions can be established, claims to theexistence of God and the occurrence of miracles areestablished neither by argument nor in experience and somust be considered as interpretative hypotheses laidupon the experienced world. The materialist must againurge that in framing hypotheses, as in seeking explana-tions, there is no sufficient reason for deserting the natu-ral for the supernatural. In such circumstances as theseconsiderations of parsimony exclude all supernaturalentities from any reasonable ontology.

Materialists must show that, contrary to the claims ofSpiritualists and Buddhists, there is no sufficient reasonto believe in survival of bodily death or in reincarnation.And indeed there are plausible arguments that both

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doctrines rest on untenable views of the self. These arguments do not impugn the possibility of bodily resur-rection, but that is compatible with materialism.

METAPHYSICS. Materialism has in the past been assailedas incomplete. Even if, in a great advance on its predeces-sors, modern cosmology does provide explanations forthe origin, persistence, and motion of the fundamentalparticles, it provides none for the initial conditions fromwhich these derive. Nor does materialism make intelligi-ble why each fundamental interaction has had one resultand not another. The reply, now widely accepted, is thatall chains of explanation must eventually come to a ter-minus and that to seek to go beyond contingent truthsconcerning the items and processes in this world is to gohunting a mare’s nest.

THE MIND AND HUMAN EXPERIENCE. There is nodoubt that our own conscious experience provides thegreatest intuitive challenge to materialism. C. D. Broad inThe Mind and Its Place in Nature (1925) formulates manypeople’s reaction to the suggestion that mental events arephysical events, such as molecular movements, takingplace in our body:

About a molecular movement it is perfectly rea-sonable to raise the question “Is it swift or slow,straight or circular and so on?” About the aware-ness of a red patch it is nonsensical to askwhether it is a swift or slow awareness, a straightor circular awareness, and so on. Conversely, it isreasonable to ask whether it is a clear or a con-fused awareness, but it is nonsense to ask of amolecular movement whether it is a clear or aconfused movement. Thus the attempt to arguethat “being a sensation of so and so” and “beinga bit of bodily behavior of such and such a kind”are just two names for the same characteristic isevidently hopeless. (p. 623)

Indeed, this attempt is hopeless, but it is not one amaterialist must make. We need to distinguish the processof being aware from the item of which we are aware. Thetwo “names” that materialists claim to name the samething are “subject S having sensation P” and “subject Sundergoing bodily changes Q,” and it has become clearsince Broad wrote that what is or is not nonsensical is notan immediate deliverance of introspection, but an issuein the fashioning of concepts to improve theories of theworld. As for P, which is the item of which S is aware—what Broad calls the sensation S has—there would be noabsurdity if this could be dealt with by a topic-neutralstrategy. We are aware that something is going on in us,

which deserves the description “red patch,” but accordingto the topic-neutral strategy, the nature of what is goingon is not part of what we are conscious of. The fact of thematter, according to the materialists, is that we have acovert presentation of bodily changes Q to the person S,who is having the sensation. Nevertheless, the two mainstumbling blocks for functionalist materialism both con-cern the character of our inner life.

The qualia problem. The topic-neutral or causal/the-oretical strategies may well be satisfactory for those innerstates that have no special “feel” about them, such asdeciding. We can decide to do something, and be awarethat we have decided, but that awareness carries no spe-cial feel or twinge or glow with it. We are aware thatsomething is going on in us, something that will have animpact on how we behave by bringing a new causal factorinto our life. But that state, and our awareness of thatstate, reveal nothing about its nature as material orimmaterial. Decisions and intentions are thus favorablecandidates for a topic-neutral analysis—so, too, is doingmental arithmetic, where the process leads to changes inwhat one will say or do, but carries no other inner char-acteristics that one is aware of.

The case is otherwise, however, with sensations andfeelings. To see a red patch is to be aware of an inner statethat has a redness about it, that sets it apart from thegreen and blue patches we see. This difference is not obvi-ously a difference in how we discriminate the two items,and react to them, as is brought out by the spectrum-shiftarguments, which point out that although your outwardcolor-vision behavior may match mine, you may see redsas I see pale pinks, or blues as I see greens.

To be in love is certainly to be in a state apt to issuein a characteristic pattern of behavior. But it is more thanthat; there is a complex of feelings involved that do not ofthemselves involve behavioral differences, but differencesin consciousness, by comparison with those not in love.

To be angry, or in pain, or delighted, carry specialsensations or feelings with them too. All such sensationsor feelings are known as qualia, and the qualia problem isthe problem of fitting them in to a materialist world view.It is notorious that when you are seeing something green,and therefore experiencing a sensation of green, there isno green physical surface anywhere inside you. The sharppangs of pain are similarly elusive—the neural activitieshave been found that occur when pain is felt, but thepainfulness of pain does not seem to be present amongthem.

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Qualia seem to be an important part of being con-scious. They seem to make a difference to how we speakand act, yet they stand outside the network of physicalcausation, neither taking energy in their production, norhaving any force to apply to change the world. They chal-lenge the deep materialist commitment to the physicalclosure of the natural world. If only physical items canhave physical effects, then qualia cannot even produceour awareness of them, nor our capacity to describethem, which makes them paradoxical items indeed.

There have been attempts to account for thembehavioristically, as dispositions to act and react in par-ticular ways. Perhaps the most promising materialist sug-gestion is that the intrinsic qualities of sensations are inreality purely schematic and enable us only to distinguishone sensation from another. Inner states notoriouslyelude direct characterization. Our attempts to describethem often proceed by comparison with other sensationsdirectly or ultimately picked out by reference to theirstimulus and/or response. For example, we describesmells as of cinnamon or of rotten eggs (stimulus) and asappetizing or nauseating (response); we speak of pains asjabbing, burning, or like “pins and needles.” Feelings ofanger, shame, pride, and fear are all described in terms ofbodily temperature.

If the sameness or difference of inner states but nottheir nature is given introspectively, sensations could wellbe states of the nervous system typically connected withstimulus and/or response, even though we are not awareof this. This strategy for dealing with qualia faces theproblems of spectrum-shift arguments, because two setsof sensations, tastes for example, could be shifted relativeto one another along a spectrum, yet perform equally wellin informing us of the sameness or difference, and typicalcauses and effects, of our inner states.

The qualia problem was long emphasized by F. C.Jackson (1998) in a series of influential articles. His mostrecent stance is the “there must be a solution” solution:Somehow, qualia must be reconcilable with materialism,even if we cannot see how.

The insight problem. The second currently mostacute problem for materialism concerns the nature ofhuman insight and understanding. When we learn tospeak a language, we acquire the ability to conduct a con-versation satisfactorily; that is, to make appropriateresponses to the speech of others, to initiate conversationsusing sounds the other recognizes and responds to. But toproperly understand, more than linguistic competence isrequired. This was dramatized by John Searle (1992) inhis “Chinese Room” argument: If someone who had no

understanding of Chinese but who could recognize Chi-nese characters were shut away in a room, and providedwith pieces of Chinese—questions and so forth—through a mailbox, that person could, using a computer-ized dictionary for example, choose appropriateChinese-character responses. This is a linguistic compe-tence that does not include understanding and is clearlydeficient by comparison with the capacity of a genuineChinese speaker. The missing component, understandingor insight, proves just as elusive as do the qualia to mate-rialist studies of the nervous system.

PHILOSOPHY. Materialism faces several other more gen-eral objections, for the most part of a logical kind, thatmust be faced.

The argument from self-destruction. A popular argu-ment for disposing of materialism is this:

All doctrines concerning the nature of the world arearrived at by inference.

Thus, a fortiori, materialism is so reached.

But if materialism is true, inference is a causallydetermined process in people’s brains, and not arational process.

Materialism is therefore a doctrine arrived at by non-rational causal processes.

Thus, if it is true, there can be no reason to think itso.

This argument has a long history, being found inEpicurus and developed and defended by J. B. S. Haldane(1932) and Karl Popper (1977). Nevertheless, it is invalid.That the course of a given process of inferring was deter-mined by the structure of a brain does not entail that itwas an unreasonable inference. Nor does it entail thatthere could be no ground for thinking it reasonable. Wecan see that this is so, by comparing reasoning in peoplewith calculating in adding machines. The result reached isa causal consequence of the structure of the machine; it isnonetheless a correct one, and one we are entitled to relyon. Haldane later retracted his argument (1954).

Asymmetrical knowledge of physical and mentalstates. Another common argument against materialismpoints out that,although ordinary people can recognizethoughts and feelings and intentions, they are completelyignorant of processes in the central nervous system, andso the mental occurrences cannot be identified with anysuch physical events. Friedrich Paulsen, for example,argued to this effect in chapter one of his Introduction toPhilosophy (1895 [1892]).

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This argument is also, as it stands, invalid. It is likearguing that because the police know some of the charac-teristics of a man who committed a crime but do notknow anything about John Smith, John Smith could notpossibly be the man who committed the crime. A similarreply is provided by Place and Smart in articles cited inthe bibliography.

The argument would be valid if another premisewere added: In introspection the full nature of mentalevents is disclosed. But there is no good reason for think-ing this premise is true.

A variation of this argument claimed that introspec-tive knowledge of our own mental states is incorrigible,whereas no knowledge of anything physical is incorrigi-ble, so mental states cannot be physical. This argumentfaded from view after Armstrong exposed its weakness:We can and do make mistakes about our own inner men-tal states.

The general nature of human reason. Keith Gunder-son (1964) revived an argument of Descartes’s to theeffect that men are not machines, even cyberneticmachines, and therefore not merely material. In allknown machines the matching or surpassing of a humanintellectual ability is a specific outcome of a specificstructure. Each skill is a skill at some specific task and noother. But in human beings, intellectual skills are general-ized and come in clusters; human reason is a tool for allcircumstances. Thus, it is not proven that the human skilland that of the machine arise from a like inner structure.On the contrary, the reasonable conclusion is that themachine’s skill and the human skill are to be explained indifferent ways—that is, a person is not any kind ofmachine.

The reply available to materialists is that this argu-ment is premature. The simulation of human perform-ance by material assemblages is in its infancy. Thereseems no reason to suppose a machine with generalizedskills impossible.

Intentionality. Unlike the situation with anythingphysical, in the realm of the mind there are relations thatcan exist even in the absence of one of their terms. Theseare the intentional relations, which include intending,believing, hoping, fearing, and desiring. The argumentfrom intentionality rests on this peculiarity and may beput this way:

A peculiarity of many mental states is their essentialconnection with an object. In intending, I mustintend something, and in hoping, I must hope forsomething.

However, whereas when I kick something, the thing Ikick must exist, the thing intended or the thinghoped for may or may not have any real existence.

In this way some mental states differ essentially fromall physical states.

Thus, materialism cannot be true.

The materialist reply to this argument is that inten-tional “relations” are strictly speaking not relations butmonadic states that are identified by reference to whatwould fulfill them or constitute their exercise. These arepossible states or circumstances that, were they actual,would be material. It is a further question