Diagramming arguments

Homework from last time:

11. Freedom of the press is an important freedom of societies. It is like the right to life with respect to individuals.

Argument, or something else (e.g., report, illustration, explanation)?


12. An agreement cannot bind unless both parties to the agreement know what they are doing and freely choose to do it. This implies that the seller who intends to enter a contract with a customer has a duty to disclose exactly what the customer is buying and what the terms of the sale are.


13. Neither the butler nor the maid did it. That leaves the chauffer or the cook. But the chauffer was at the airport when the murder took place. The cook is the only one without an alibi for his whereabouts. Moreover, the heiress was poisoned. It’s logical to conclude that the cook did it.


14. If a piece of information is not “job relevant,” then the employer is not entitled qua employer to know it. Consequently, since sexual practices, political beliefs, and associational activities are not a part of most job descriptions, employers qua employers are not entitled to information about them from a prospective employee. And since they do not directly affect one’s job performance, they are not legitimate information for any employer to know in the determination of hiring a job applicant.


15. Parents who were abused as children are themselves more often violent with their own children then parents who were not abused. This proves that being abused as a child leads to further abuse of the next generation. Therefore, the only way to stop the cycle of child abuse is to provide treatment for abused children before they themselves become parents and perpetuate this sad and dangerous problem.

Diagramming Arguments

Phil 57 section 3San Jose State University

Fall 2010

Arguments

• Claim that is supported (conclusion)• Claims that offer support/reasons in favor of

believing the conclusion (premises)

Sometimes it takes some work to identify conclusion and premises!

Diagramming arguments

• Number the claims (1, 2, 3, …)• Use “+” to indicate that two or more premises

work together to support a conclusion.• Use a line ( _______ ) under premises and

above the conclusion they support.

Diagramming arguments: an example.

“There cannot be any emptiness; for what is empty is nothing, and what is nothing cannot be.”

First: number the claims.

(1) There cannot be any emptiness (2) what is empty is nothing(3) what is nothing cannot be.

Useful to break out and number individual claims, even if they’re in the same sentence.

Next: work out relations of support.

(1) There cannot be any emptiness (conclusion)(2) what is empty is nothing (premise)(3) what is nothing cannot be. (premise)


(2) what is empty is nothing (premise)(3) what is nothing cannot be. (premise)_____________________________________(1) There cannot be any emptiness (conclusion)

(2) + (3)(1)

Another argument

“Lentils are healthy. There are many reasons for this. They reduce heart disease. They are a great source of fiber and protein. And, they are low in fat and simple carbohydrates.”


(1) Lentils are healthy. (2) There are many reasons for this. (3) They reduce heart disease. (4) They are a great source of fiber and protein.(5) They are low in fat and simple carbohydrates.


(1) Lentils are healthy. (2) There are many reasons for this. (3) They reduce heart disease. (4) They are a great source of fiber and protein.(5) They are low in fat and simple carbohydrates.Each premise here provides an independent

reason to accept the conclusion.


(2) There are many reasons for this. (1) Lentils are healthy.

(2)(1)


(3) They reduce heart disease. (1) Lentils are healthy.

(3)(1)


(4) They are a great source of fiber and protein.(1) Lentils are healthy.

(4)(1)


(5) They are low in fat and simple carbohydrates.

(1) Lentils are healthy.

(5)(1)

Relations of support for whole argument:

(2) (3) (4) (5)(1)

No “+” because the premises don’t need to be together to support the conclusion.

(Any one of them alone is enough to support the conclusion.)

Diagramming arguments: an example.

“You should vote for the ballot measure that legalizes and taxes marijuana in California. California’s state budget is hurting, and new tax revenue will help. Plus, the state spends too much incarcerating people for possession of marijuana. If the ballot measure passes, marijuana will be legal and we won’t spend so much money on jails.”


(1) You should vote for the ballot measure that legalizes and taxes marijuana in California.

(2) California’s state budget is hurting(3) New tax revenue will help the state budget(4) The state spends too much incarcerating people

for possession of marijuana. (5) If the ballot measure passes, marijuana will be

legal and we won’t spend so much money on jails.”


(1) You should vote for the ballot measure that legalizes and taxes marijuana in California.

(2) California’s state budget is hurting(3) New tax revenue (from taxing marijuana) will

help the state budget(4) The state spends too much incarcerating people

for possession of marijuana. (5) If the ballot measure passes, marijuana will be

legal and we won’t spend so much money on jails.”


(2) California’s state budget is hurting(3) New tax revenue (from taxing marijuana) will

help the state budget_____________________________________(1) You should vote for the ballot measure that

legalizes and taxes marijuana in California.(2) + (3)

(1)


(2) California’s state budget is hurting(4) The state spends too much incarcerating people for

possession of marijuana. (5) If the ballot measure passes, marijuana will be legal

and we won’t spend so much money on jails.___________________________________(1) You should vote for the ballot measure that legalizes

and taxes marijuana in California.(2) + (4) + (5)

(1)


Both pieces of the argument together:(2) + (3) (2) + (4) + (5)

(1)Premises 2 and 3 work together to support

conclusion.Premises 2, 4, and 5 work together to support

conclusion.

Homework – diagram the argument

1. Whatever doesn’t kill me makes me stronger. The amount of coffee I drink is a lot, but it hasn’t killed me. So all that coffee makes me stronger.


1. Whatever doesn’t kill me makes me stronger. The amount of coffee I drink is a lot, but it hasn’t killed me. So all that coffee makes me stronger.


2. Time is either real or unreal. Space is real. Time cannot be separated from space. If something is real, and another thing cannot be separated from it, then that thing must also be real. So, time is real.


2. Time is either real or unreal. Space is real. Time cannot be separated from space. If something is real, and another thing cannot be separated from it, then that thing must also be real. So, time is real.


3. Jewish dietary law defines as “kosher” only meat from particular kinds of animals. Mammals that have cloven hooves and that chew their cud can be kosher, but mammals missing one of these two are not. (So rabbits, which ruminate but don’t have hooves, are not kosher.) Fish must have both fins and scales to be kosher. Milk and meat must not be consumed in the same kosher meal. (Fish don’t count as meat or dairy in this reckoning.) All of this means that the Aigi Kampoi (a fish-tailed goat of folklore) would be kosher because it has cloven hoofs, chews its cud, and has fins and scales. However, it would still be considered a meat meal, even though it’s partially fish. So you can’t eat dairy with it.


3. Jewish dietary law defines as “kosher” only meat from particular kinds of animals. Mammals that have cloven hooves and that chew their cud can be kosher, but mammals missing one of these two are not. (So rabbits, which ruminate but don’t have hooves, are not kosher.) Fish must have both fins and scales to be kosher. Milk and meat must not be consumed in the same kosher meal. (Fish don’t count as meat or dairy in this reckoning.) All of this means that the Aigi Kampoi (a fish-tailed goat of folklore) would be kosher because it has cloven hoofs, chews its cud, and has fins and scales. However, it would still be considered a meat meal, even though it’s partially fish. So you can’t eat dairy with it.


4. If morality requires freedom, and punishment requires morality, it follows that punishment requires freedom.


4. If morality requires freedom, and punishment requires morality, it follows that punishment requires freedom.


5. God is all-powerful, all-loving, and all-knowing. Since God is all-powerful, he has the capacity to rid the world of evil. Since God is all-knowing, he has the capacity to know where and when evil occurs. Since God is all loving, he wants to get rid of evil in the world. However, there is evil in the world. Thus, God does not exist.


5. God is all-powerful, all-loving, and all-knowing. Since God is all-powerful, he has the capacity to rid the world of evil. Since God is all-knowing, he has the capacity to know where and when evil occurs. Since God is all loving, he wants to get rid of evil in the world. However, there is evil in the world. Thus, God does not exist.


6. Some things that exist are caused by other things. Nothing can be the cause of itself. Nor can there be an endless string of objects causing other objects to exist. Therefore, there must be an uncaused first cause: God.


6. Some things that exist are caused by other things. Nothing can be the cause of itself. Nor can there be an endless string of objects causing other objects to exist. Therefore, there must be an uncaused first cause: God.

Education

Diagramming arguments