What is Epistemology?

A General Theory of Knowledge and Justified Belief.

Three Elements of the General Theory:

1. Epistemic Principles. Two kinds:

(a) Logical analysis (not definitions!) of important concepts (e.g., K à TB).

(b) Principles of Rational Belief, including Principles of Rational Belief Change (e.g., It is irrational to have logically inconsistent beliefs.)

2. Particular epistemic judgments: Judgments about particular cases of knowledge and justified belief: What do we know and what are we justified in believing?

The Application of the General Theory to Itself Raises Two Further Questions:

The Metaphysics of Epistemology: What is the metaphysical status of epistemic principles and particular epistemic judgments?

The Epistemology of Epistemology: How can we know or be justified in believing epistemic principles and particular epistemic judgments.

REASONING ABOUT REASONING

1. Top-Down Reasoning and the Proof Paradigm

2. Bottom-Up Reasoning: Induction and Abduction.

3. Equilibrium Reasoning

A SAMPLE DEDUCTIVELY VALID ARGUMENT

PREMISES:

EP1. Justified, True, Belief that pà Knowledge that p

PEJ1. I am justified in believing that I exist PEJ2. I exist is true                              

CONCLUSION: PEJ3. I know that I exist.

Deductively valid arguments play a role in BOTH Top-Down and Bottom-Up reasoning. You should be able to explain how, in different circumstances, the above deduction could play a role in each kind of reasoning.

Hume's Epistemology

Theory of What Reason Can and Cannot Do

A. Reason can determine:

(1) Relations of Ideas (Rational intuition).

(2) Deductive Reasoning

(3) Apply (1) and (2) to current perception and memory.

B. Reason cannot do anything else.

Other ancillary premises

CONCLUSIONS: (1) We have no good reason to believe in causal relations. (They are explained by Habit or Custom.)

(2) We have no good reason to believe in bodies (physical objects). (Constancy and Coherence explain but do not justify such beliefs.)

(3) We have no good reason to believe anything about the future. (They are explained by Habit or Custom.)

A SAMPLE INDUCTION

(1) In the past, all observed emeralds have been green.

(2) The future will be like the past.

Therefore, in the future, all observed emeralds will be green.

A RECONSTRUCTION OF HUME'S ARGUMENT THAT THERE CAN BE NO INDUCTIVE JUSTIFICATION OF INDUCTION

(1) In the past, the future has been like the past.

(2) The future will be like the past.

Therefore, in the future, the future will be like the past.

But the conclusion just repeats premise (2). The proffered justification is circular!

GOODMAN'S NEW RIDDLE OF INDUCTION

(1) In the past, all observed emeralds have been grue.

(2) The future will be like the past.

Therefore, in the future, all observed emeralds will be grue.

grue = green if observed before Jan. 1, 2008; otherwise blue.

bleen = blue if observed before Jan. 1, 2008; otherwise green.

Note that "blue" and "green" can be defined in terms of "grue" and "bleen".