Transition to Immanuel Kant

Rationalism and Empiricism

Historical Overview

Rationalism

Descartes Spinoza

Leibniz

Empiricism

Locke Berkeley

Hume

Wolff

Kant

Empiricism

• Basic tenets of Empiricism– All knowledge comes from experience– The mind is a blank slate (tabula rasa)– The mind is passive, merely a receptor of sense impressions

• Hume’s radicalizes these, ending in Skepticism– Unbridgeable gap between sense impressions and objects in the world– All we know are ‘sensations’ playing in our minds– The necessary ‘connectedness’ of experience is problematic Causality is

merely superstition, born of habit

Rationalism

• Basic tenets of Rationalism– Reason has access to reality as it really is– Reason can go beyond what is given to us in experience– Reason can then grasp things, not as they appear, but as they really

are

• The Leibniz-Wolffian School– Reason (without experience) can know about God, immortality of the

soul, and human freedom

• Reason has direct access to “meta-physical” knowledge

Part 2

• John Locke• David Hume• Immanuel Kant• Thomas Bayes• Karl Popper• Thomas Kuhn• Imre Lakatos

John Locke (1632-1704)

Introduction

John Locke

Biography• B. 1632, son of a small property-owner and lawyer• Oxford, 1652-67• Studied church-state issues, chemistry and medicine, new mechanical

philosophy • Involvement in politics through Lord Ashley, whom he treated for a liver

abscess• Plotted to assassinate King Charles II and his Catholic brother, later James

II • Exile in Holland, 1683-89• 1689: 3 major works published

Major works and themes:

A Letter Concerning Toleration (1689)- Argues for religious toleration; - Except for atheists, “who deny the Being of a God” and thus

cannot be trusted to keep their promises (e.g. in contracts).Context:- Religious wars and persecution in England and on the

Continent.

Works, cont.Essay Concerning Human Understanding (1689)• Argues against innate ideas • For the acquisition of knowledge through the senses:

“Intuitionism” • Anti-Cartesian (Descartes)• Re-opens debate about essentialism vs conventionalism with

his views on identity, comparison, classification and natural kinds.

Works, cont.

Two Treatises on Government (written 1679/80; published 1689/90)

• First: Argues against traditional basis for political authority expressed in Filmer’s Patriarcha, divine right of kings;

• Second: protection of private property, life and liberty = basis for civil government.

Locke’s Basic Epistemology

• Human being = tabula rasa (blank slate)• receives sense-impressions• some of these transformed by Mind into Ideas • Ideas represented in language by words• However, no Ideas are innate• Mind operates (through gradual learning process) w/out reference to any

received authority (of Church, State or others)

Complex Ideas

• Sense-data of primary qualities (PQs) and secondary qualities (SQs), produce ideas in the mind:

• Ideas are mental results of sense-data • -Sense-perceptions• -Bodily sensations• -Mental images• -Thoughts and concepts

Primary(PQ) and Secondary Qualities(SQ)

Distinction between perceived aspects of things. The primary qualities are intrinsic features of the thing itself (its size, shape, internal structure, mass, and momentum, for example), while the secondary qualities are merely its powers to produce sensations in us (its color, odor, sound, and taste, for example). This distinction was carefully drawn by Galileo, Descartes, Boyle, and Locke, whose statement of the distinction set the tone for future scientific inquiry. But Foucher, Bayle, and Berkeley argued that the distinction is groundless, so that all sensible qualities exist only in the mind of the perceiver.

Attacks Innatism (Descartes)Locke’s objections to innate ideas (“II’s”)• Lack of universal assent: II’s not known to idiots, children,

illiterates • Dependence on authority:• “…a Man is not permitted without Censure to follow his own

Thoughts in the search of Truth, when they lead him…out of the common Road”.

• Epistemological and political commitment to the individual (who is the foundation of Locke’s political liberalism).