2. Aristotle’s Metaphysics
In regards to man, he asked,
“Why is this one and not many
— rational and animal?”
(1037b13-14).
Thus, the classical definition
of man is that of a “rational
animal”.
So sayeth a really smart dude.
3. Man as a Rational Animal
Our mythologies
are full of
creatures that
seem to explore
the idea that man
is part animal.
Often, these
humanoid
creatures lack the
ability to reason.
4. Not Everyone Agrees…
“It has been said that man is a rational
animal. All my life I have been searching
for evidence which could support this.”
Bertrand Russell
“Man is a rational animal who always loses
his temper when called upon to act in
accordance with the dictates of reason.”
Oscar Wilde
5. Wason Card Selection Task 1
A D 7 4
Rule: If a card has a vowel on one side, then it has
an even number on the other side.
Select those cards that you definitely need to
turn over to find out whether or not they violate
the rule.
6. Wason Card Selection Task 2
Drinking
a beer
Drinking
a
Coca-Col
a
14-year-
old
20-year-
old
Rule: In Switzerland, it is against the law for a
person under the age of 16 to consume alcohol.
Select those cards that represent people you
definitely need to check in order to find out
whether or not they are breaking the law.
7. What is the difference?
The two problems are, from a logical
perspective, identical.
The second is contextualized in the world
of social and biological reality. (Remember the
importance of context when interpreting data.)
The second is involved with truth telling
and social cheating.
8. Are we that rational?
Some scientists, like
evolutionary psychologist
Leda Cosmides, believe
that the human mind is not
well adapted to solve
rarefied problems of logic,
but quite refined and
powerful when it comes to
dealing with matters of
cheating and deception.
Dr. Cosmides in a
2016 lecture at the
University of
California, Santa
Barbara
9. Which is the Better Deal?
Would you accept a gamble that offers 10%
chance to win CHF.95 and a 90% chance to
lose CHF.5?
—or—
Would you pay CHF.5 to participate in a lottery
that offers a 10% chance to win CHF.100 and
a 90% chance to win nothing?
10. Reason and Logic
What is logic?
It is not the science of the laws of thought.
It is not the science of reasoning.
Logic is the study of the methods and
principles used to distinguish good or
correct reasoning (valid) from bad or
incorrect (invalid) reasoning.
11. Inductive Logic
Also known as induction, or inductive
reasoning
Inductive logic is reasoning in which the
conclusion does not follow with absolute
necessity.
All of my English classes have been interesting so far.
Therefore, it is likely my next English class will be
interesting.
12. Inductive Logic
● Inductive logic is not concerned with the
absolute certainty of an argument.
● It gives good reasons (empirical evidence)
for supporting a conclusion but it does not
guarantee that conclusion.
● The reliability of the empirical evidence on
which we base our conclusions
determines the soundness of the
argument.
13. Deductive Logic
Also known as deduction or deductive
reasoning.
Deductive logic is concerned with the rules for
determining when an argument is valid.
14. Syllogisms
A syllogism is an argument that consists of
three lines. The last line is called the
conclusion. The first two lines are
propositions. When propositions are used in a
syllogism they are referred to as premises
(singular, premise).
15. Validity, Not Truth
In logic we are concerned with the logical
form of an argument rather than the
content of its propositions.
We use the words valid and invalid to
describe the form of the argument. The
above syllogism is valid.