Self-Knowledge, Philosophy, and Decision-Making: Key Concepts and Paradoxes

Traditional view of self-knowledge

Knowledge of experiences is immediate and infallible.

Problems with traditional view

Expectation effects (pain, cold, itch), illusions (moon size), motivated self-deception, emotional confusion, brain trauma.

Alternative view of self-knowledge

Like external perception: fallible, malleable, influenced by top-down processes (Gestalt shifts, McGurk effect).

Plato's Cave allegory

Prisoners mistake shadows for reality; leaving cave = awakening to true forms.

Themes from Plato's Cave

1. Ordinary experience doesn't depict true reality. 2. "Getting out" is worthwhile — seeing real truth transforms life.

Skeptical view

Appearances known, but reality inaccessible.

Realist view

Only hidden "real" truths (like physics) matter; appearances are fictions.

Criticism

Human experience is still "our" reality — not all appearances are illusory.

Hume's "old riddle"

Why assume the future will be like the past? Circular reasoning if justified by past success.

New riddle of induction

The question isn't "will the future be like the past?" but "in which respects will the future resemble the past?"

Curve-fitting problem

Many possible rules fit past data; which one is the "real" projection?

Goodman's "grue" paradox

Emeralds are "grue" if green before time t or blue after t; why project "green" not "grue"?

Underdetermination

Data underdetermines which hypothesis is correct; projection requires more than fit.

True positive

Test is positive and you have the disease.

True negative

Test is negative and you don't have the disease.

False positive

Test is positive but you don't have the disease.

False negative

Test is negative but you do have the disease.

Base rate fallacy

Ignoring low prevalence → overestimating risk after a positive test.

Conjunction fallacy (Linda case)

People judge "bank teller + feminist" as more likely than just "bank teller."

Representativeness heuristic

Judging probability by how typical something seems, not by actual statistics.

Real-world distortions

Polygraph tests (false positives), prosecutor's fallacy (blood match odds), stereotype reliance (NBA example).

Sample bias

Non-representative samples (e.g., call-in polls) distort projection.

Regression to the mean

Extreme cases tend to be followed by more moderate ones; misleads about cures or punishments.

Prisoner's Dilemma

Rational to defect, but mutual defection worse than mutual cooperation.

Problem of the Commons

Individual exploitation of shared resources seems rational but leads to collapse (overgrazing, overfishing, climate).

Free rider problem

Individuals benefit from group cooperation without contributing.

Moral/Political examples

Arms races, not voting, boycotts, standing up to bullies.

Takeaway

Individual rationality can create collective irrationality → justifies norms, agreements, and moral codes.