What Can We Know and How Can We Know It?

1. What Can We Know and How Can We Know It? Notes to Introduce Philosophical Discussion

2. The Fields of Philosophy • Metaphysics – the study of the nature of reality. • Epistemology – the study of the nature of knowledge • Axiology – the study of the nature of value. • Ethics –values in the realm of morality • Aesthetics– values in the realm of beauty and art • Logic – principles of right reasoning

3. Logic • The Three Laws of Thought • The Law of Non-contradiction • The Law of Excluded Middle • The Law of Identity

4. Logic • The difference between deductive and inductive logic • Inductive Logic • The premises suggest the conclusion. • Deductive Logic • The premises guarantee the conclusion.

5. Logic -- Deductive Reasoning • The Categorical Syllogism • Premise 1: All A is inside B • Premise 2: All B is inside C • Conclusion: All A is inside C

6. Epistemological Questions • What is the proper definition of truth? • Options: • Correspondence • Coherence • Pragmatism • Is truth absolute or is it relative? • Are there some things that are true objectively? • What can we know? Can we know the answers to life’s greatest questions?

7. Epistemological Questions • What are legitimate sources of truth? • Options: • Experience • Reason • Revelation (authority) • General Revelation • Special Revelation • Should the Bible be considered a legitimate source of truth? • Is science the new ultimate standard for truth? • Has the “scientific method” usurped philosophical inquiry and biblical authority?

8. Rationalism • The Rationalism of Plato • Knowledge is possible because it is innate. • Fundamental ideas or principles are built right into the mind itself and require only to be developed and brought to maturity.

9. Rationalism of Plato • We have acquired these innate ideas in our pre-existent state. • Prior to its embodiment in this world, the soul was in the presence of the forms, where it acquired knowledge of the realities. • The trauma of being born causes us to forget this knowledge, but we recall it as we begin to have imperfect contact with the sensible world. Our senses provide an initial stimulus to the recollection of our innate ideas.

10. The Rationalism of Descartes • How Descartes found Certain Knowledge • He doubted everything doubtable. • in order to find one thing that was undoubtable. • He would build his knowledge upon this one undoubtablething. • The one undoubtable thing: He was a thinking substance. • “I doubt; therefore I think.” • “I think; therefore I am.”

11. Empiricism • What is Empiricism? • Empiricism—the view that all knowledge is derived from senseexperience.

12. John Locke’s Empiricism • The mind is a tabula rasa (“blank tablet”) before the input of experience. • Locke’s epistemological dualism: The two factors involved in knowledge are (1) mind which knows, and (2) its ideas which are known. • The ego-centric predicament: If we know only our ideas directly, how can we be certain of their correspondence with things in the external world?

13. Radical Empiricism -- Hume • David Hume: The source of all knowledge is perceptions. • All ideas are derived from impressions – vivid or lively sensations.

14. Though we have a natural belief in self and causality (every event must have a cause), experience gives us no rational knowledge of either of these; therefore we must be skeptical of their reality. • Hume’s position is known as phenomenalism: All we can actually know is the phenomena or appearances presented in our perceptions.

15. Skepticism • Varieties of Skepticism • Common-sense skepticism: healthy incredulity about unlikely or preposterous claims. • Philosophical skepticism: doubt about cherished philosophical ideas. • Absolute skepticism: the denial of knowledge itself.