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