Psychology 2800E Thursday, September 13, 2012
Ways of Knowing
Part 1: How Do We Know?
CHARLES PEIRCE(1877):T HE “FIXATION OFBELIEF”
a. E.g., we believe most of the things, accept authority of textbooks; as patients,
we take pills doctors prescribe because we assume the doctor would know
what is good for us. There is nothing inherently wrong as authorities usually
provide us with accurate knowledge.
b. But, authorities can be wrong
c. Cast on knowledge that is incomplete, biased, or simply wrong
d. Prescribe wrong medicine, wrong diagnoses, etc.
B. Logical Discourse (the “a priori” method)
a. Knowledge that’s “agreeable to reason”
Example: Deductive logic (syllogisms):
Begin with general premises (believed, a priori, to be true);
Deduce specific conclusions (new knowledge)
Example: Do kangaroos have livers?
Premise 1: All kangaroos are mammals,
Premise 2: All mammals have livers,
Conclusion: All kangaroos have livers.
You can answer this question through this syllogistic process.
Problem #1: The premises might not be true:
Premise 1: Socrates was a dog
Premise 2: Dogs are not human
Conclusion: Socrates was not human
If one premise is not true, then the conclusion might not be true.
Problem #2: “Logical errors”:
Premise 1: All welfare is “giving to the poor”
Premise 2: All charity is “giving to the poor”
Conclusion: All welfare is charity. But is it?
If both premises are true, then is the conclusion also true?
Premise 1: All Canadians are people
1 Thursday, September 13, 2012 Psychology 2800E
Premise 2: All Egyptians are people
Conclusion: All Canadians are Egyptians???
You can’t draw a conclusion from those premises.
Relying on logical discourse or a priori method is not an infallible way of knowing.
C. Empiricism: Relying on direct experience and observations.
“Experience is the best teacher”
The value of empiricism as a way of knowing, “straight from a horse’s mouth”
Anecdote: philosophers were debating number of teeth in a horse’s mouth;
horses are less sacred than cows and therefore have fewer teeth (28). Deductive
logic: premise 1: horses belong to same family as zebras; premise 2: zebras have 38
teeth; conclusion: horses must also have 38 teeth (based on a priori reasoning).
Another philosopher suggested that if we want to know how many teeth there are,
we should find a horse, open its mouth, and count the number of teeth. That
philosopher was an empiricist.
Problems occur when we rely too much on “subjective empiricism”:
Informal, “intuitive” experiences and observations
1. Knowledge we gain is too general (it describes everything; but predicts
E.g., Common Sense (conventional wisdom)
- “Haste makes waste”, BUT
- “He who hesitates is lost”;
- “Two heads are better than one”, BUT
- “Too many cooks spoil the soup”
Note: It’s not that common sense is wrong; instead, we don’t know when
- Don’t know specific conditions when it applies
- As such, it can never be disconfirmed.
2. Subjective experience and observations are often biased:
Philosopher empirical wasn’t relying on authority but on direct
experience, that philosopher could’ve been seriously misled if just relying
on informal experience (Gum disease, baby horse, etc.)
- The availability bias: events that are available in memory are
judged to be more frequent.
o Tendency for people to assume events that are easily
available in memory are more frequent in the real world
But, this is not always the case!
- Example 1: in the English language, which is more frequent?
o Words beginning with “k” OR
o Words with “k” as third letter
2 Psychology 2800E Thursday, September 13, 2012
Easier to retrieve from memory words beginning
with letter “k” – more available in memory,
therefore judging to be more frequent
Words with “k” as third letter are more than twice as
Most people choose (1 because easy to retrieve), but
(2) is 2 times more frequent!
Example 2: Some events are easier to imagine (makes them available in memory, so judged
to be more frequent)
What is the more likely cause of death (i.e., which is more frequent)?
1. Being killed by “shark attack” OR
2. Being killed by “falling airplane part”
- (2) is 30 times more likely!
Most people would choose (1), because it is easier to imagine the o