PHIL 102A

TEXT OF TRANSPARENCIES FOR WEEK #1 (Sept. 30 - Oct. 4)

IMPLICATION

Example: The proposition that Bill is a father IMPLIES the proposition that Bill is male, because the property of being a father IMPLIES the property of being male

(Father --> Male).

In ordinary language, we have a number of ways of expressing IMPLICATION:

Father --> Male

All fathers are (must be) males.

Anyone who is a father is (must be) male.

A father has to be male.

If you're a father, you are (must be) male.

You cannot be a father without being male.

It is not possible to be a father and not be a male.

TEST FOR IMPLICATION: Is it possible to be a Father and not be Male?

MUTUAL IMPLICATION

The property of being a sister implies the property of being female and the property of being a sibling. All sisters are females and they are siblings.

Sister --> Female & Sibling

TEST FOR IMPLICATION: Is it possible to be a sister and not be a female or not be a sibling?

The property of being a female sibling implies the property of being a sister. All female siblings must be sisters.

Female & Sibling --> Sister

TEST FOR IMPLICATION: Is it possible to be a female sibling and not a sister?

NOT ALL NECESSARY AND SUFFICIENT CONDITIONS ARE DEFINITIONS

In Euclidean geometry, the property of being a triangle (figure with three angles) and the property of being a trilateral (figure with three sides) mutually imply each other

(Triangle <--> Trilateral),

because Triangle --> Trilateral

AND Trilateral --> Triangle.

In this course, we will use the phrase 'just in case' to express MUTUAL IMPLICATION

Something is a triangle just in case it is trilateral.

EXAMPLE OF MORAL REASONING

PREMISES: 1. Abortion is Murder

2. Murder is Wrong

CONCLUSION: Abortion is Wrong.



PREMISES: 1. A --> M

2. M --> W

CONCLUSION: A --> W.

AN ELABORATION OF THE SAMPLE ARGUMENT ON ABORTION

PREMISES:

(1) Abortion --> Killing an innocent human being

(2) Killing an innocent human being --> Murder
CONCLUSION: Therefore, Abortion --> Murder

PREMISES: (1) A --> KIHB

(2) KIHB --> M

CONCLUSION: Therefore, A M

DEMONSTRATIVE vs. DIALECTICAL REASONING

A. FORM OF A DEDUCTIVE ARGUMENT

PREMISES --> CONCLUSION

VALID ARGUMENT: When the premises imply the conclusion, we say that the argument is VALID.

PROOF (DEMONSTRATIVE REASONING): When the argument is valid AND the premises are self-evident (i.e., no rational person could doubt them), then the argument is a PROOF.

DEMONSTRATIVE REASONING (PROOF) is a one-way street, because the reasoning goes in one direction only (from the Premises to the Conclusion).

DIALECTICAL REASONING

Not All Arguments Are, Or Purport To Be, PROOFS. In most contexts, REASONING is not meant to PROVE things, but to MAKE SENSE of things.

DIALECTICAL REASONING: Dialectical reasoning is non-demonstrative reasoning by which we attempt to improve the COHERENCE of our beliefs (so they make more sense).

DIALECTICAL REASONING is a two-way street. In Dialectical Reasoning, when an argument is VALID, it requires EITHER that we accept the Conclusion, OR that we deny one of the Premises.

NORMATIVE/EVALUATIVE Terms and Statements contrasted with PURELY DESCRIPTIVE Terms and Statements

NORMATIVE TERMS are terms that have ACTION-GUIDING [PRESCRIPTIVE/ PROSCRIPTIVE] force. Some common normative terms are: ought; duty; obligation; permissible; and forbidden. When applied to actions, appropriate and inappropriate are normative terms. [Note that not all NORMATIVE terms are MORAL terms. For example, ought can be used in a NON-MORAL, PRUDENTIAL sense, as in: One ought to eat nutritious foods.]

EVALUATIVE TERMS are terms that express approval or disapproval. Some common evaluative terms are: good; bad; excellent; and awful. EVALUATIVE TERMS can express moral approval or disapproval, but can also express other types of non-moral approval or disapproval (e.g., The statement that apples taste good is a non-moral evaluative statement).

NORMATIVE/EVALUATIVE STATEMENTS are statements that include at least one normative/evaluative term. For example, moral statements about what one ought or ought not to do (e.g., the statement that one ought not to steal or the statement that one ought to tell the truth) are NORMATIVE, because they contain the NORMATIVE term ought. [Note that not all normative statements are moral. See above, for an example of a normative prudential statement.]

PURELY DESCRIPTIVE TERMS are terms that are NOT NORMATIVE and NOT EVALUATIVE.

PURELY DESCRIPTIVE STATEMENTS are statements that contain only PURELY DESCRIPTIVE terms (no NORMATIVE or EVALUATIVE terms).

[Note that Normative/Evaluative statements can contain SOME Purely Descriptive terms, but Purely Descriptive statements cannot contain ANY Normative/Evaluative terms.]

TWO KINDS OF REASONS FOR ACTION

DESCRIPTIVE REASONS for an agent A's doing an act X: PURELY DESCRIPTIVE statements which explain why A actually did X or actually will do X. Descriptive reasons explain an agent's actual behavior, usually in terms of her actual motivation.

NORMATIVE (PRESCRIPTIVE/PROSCRIPTIVE) REASONS: NORMATIVE STATMENTS which explain why A ought/ought not to perform act X PRESCRIPTIVE reasons for A to do X are reasons that A ought to do X.

PROSCRIPTIVE reasons for A not to do X are reasons that A ought not to do X.

NOT ALL NORMATIVE REASONS ARE MORAL: VARIETIES OF NORMATIVE REASONS

(1) Etiquette

(2) Law

(3) Prudential

(4) Instrumental

(5) Moral

MORAL REASONS ARE NORMATIVE REASONS, WHERE THE OUGHT IS ONE OF MORAL OBLIGATION.

Thus, even if A does act X, and even if there is a descriptive reason for A's doing X, A may be subject to moral criticism if there is a (normative) moral reason not to do X, because that would be a reason that A morally ought not to have done X.

IMPORTANT MORAL TERMS

1. MORALLY PERMISSIBLE/IMPERMISSIBLE/REQUIRED

An act A is MORALLY REQUIRED <-->

[just in case] the agent MORALLY OUGHT to do A.

An act A is MORALLY PERMISSIBLE <--> [just in case]

-A is not MORALLY REQUIRED.

(abbreviation: A is MP <--> -A is -MR.)

An act A is MORALLY IMPERMISSIBLE [i.e., MORALLY WRONG] <-->[just in case] -A is MORALLY REQUIRED.

(abbreviation: A is -MP <--> -A is MR.)

An act A is SUPEREROGATORY <--> A is morally praiseworthy, but not morally required (i.e., A is above and beyond the call of duty).

SOME TYPES OF NORMATIVE MORAL THEORIES

I. Consequentialist theories = theories according to which the rightness or wrongness of an act depends solely on the effects of the act

1. Act Utilitarianism [the most common type of Consequentialist theory] = One ought to always choose the act that will maximize total (or average) utility (where utility is understood as some sort of measure of happiness (e.g. the total of pleasure over pain)).

2. Rule Utilitarianism = One ought to act according to rules which, if generally applied, would maximize total (or average) utility.

II. Non-Consequentialist Theories: theories according to which the rightness or wrongness of an act depends on more than just its effects.

1. Deontological/Duty-Based Theories: For example, duties based on Kant's Second Version of the Categorical Imperative: Never treat another person as a means only, but also as an end.

2. Rights-Based Theories: Duties based on universal rights, which cannot be overridden by utilitarian calculations (i.e., rights trump utilitarian calculations).

3. Perspectivalism = Usually includes some minimal universal rights or obligations. Other obligations depend on special relationships (e.g., relevant relationships typically include family, friend, community, nation, humanity).