The Search for Knowledge Chapter 3 The Search for Knowledge

Charting the Terrain of Knowledge Epistemology The area of philosophy that deals with questions concerning knowledge and that considers various theories of knowledge

Charting the Terrain of Knowledge Types of knowledge -Knowledge by acquaintance -Competence knowledge -Propositional knowledge Knowledge as true justified belief -Necessary and Sufficient Conditions

The Issue of Reason and Experience Analytic statements “All Bachelors are Unmarried” “All bodies are Extended” “All Triangles have three sides” Synthetic statements “All creatures with hearts have kidneys” “drinking Water quenches thirst” “sugar is sweet” A priori knowledge A posteriori knowledge

Three Epistemological Questions Is it possible to have knowledge at all? Does reason provide us with knowledge of the world independently of experience? Does our knowledge represent reality as it really is?

Perspectives on Knowledge Skepticism Rationalism Empiricism Constructivism Relativism

Skepticism We do not have knowledge Universal (or global) skepticism Limited (or local) skeptics

General Skeptical Argument We can find reasons for doubting any one of our beliefs. It follows we can doubt all of our beliefs. If we can doubt all our beliefs, then we cannot be certain of any of them. If we do not have certainty about any of our beliefs, then we do not have knowledge. Therefore, we do not have knowledge. Is the skeptical argument consistent? Is the skeptical argument practical?

Early Greek Skeptics Cratylus Pyrrho Carneades

Rene Descartes The quest for certainty Methodological skepticism Meditations of First Philosophy

Meditations of First Philosophy Meditation I: Universal Belief Falsifier The role of thought experiments Doubting of senses: Sensory illusions, dreaming, etc. Mathematics: The possibility of a “malicious demon”

Meditations of First Philosophy Meditation II -One point of Certainty -”I am, I exist” or cogito ergo sum (I think, therefore I am)

Three Anchor Points of Rationalsim Reason is the primary or most superior source of knowledge about reality Sense experience is an unreliable and inadequate route to knowledge The fundamental truths about the world can be known a priori: They are either innate or self-evident to our minds

The Rationalist Perspective on Epistemology Knowledge is possible Only through reason can knowledge be obtained Beliefs based on reason represent reality

Socrates on Epistemology We can distinguish true from false Standards for distinguishing true from false are based on reason Rational knowledge gives us an adequate picture of the world

Plato on Epistemology Difference between knowledge and opinion must be rationally justified Agrees with Socrates that reason is able to provide knowledge of the real world Our knowledge of the world of sense is dependent on reason The world of sense is “less real” than the world understood through reason Knowledge and reality are universal, permanent and perfect The world of sense is in constant flux, impermanent, and so an unreliable basis to justify knowledge

Phaedo perfect Justice, Beauty, Goodness, and Equality We have never seen these things, yet we know they exist WE can make judgements based on our knowledge of such concepts Knowledge of perfect things must be innate Doctrine of recollection

Plato on Universals Universals or Forms Universals are unchanging; experiential reality is in flux Anything we can know about the material world through our senses depends on the corrective function of reason and the discovery of permanent and consistent principles of change (e.g. universal laws of nature)

Rene Descartes, Rationalist Methodological doubt One point of certainty: “I am, I exist” or cogito ergo sum Something cannot arise from nothing, and there must be at least as much reality in the cause as in the effect

Descartes’ Meditation III Innate ideas Principle of sufficient reason Idea of a perfect God Because Descartes is not perfect, the source of the idea of God (which includes perfection) must be God

Three Anchor Points of Empiricism The only source of genuine knowledge is sense experience Reason is an unreliable and inadequate route to knowledge unless it is grounded in sense experience There is no evidence of innate ideas within the mind that are known apart from experience

John Locke’s Perspective on Epistemology Rejection of innate ideas Knowledge is possible Simple ideas (ideas of sensation, ideas of reflection) Complex ideas Activities of the mind Compounding Relating abstracting Reasons not sufficient for knowledge of the world Knowledge represents reality Primary qualities (objective) Secondary qualities (subjective)

George Berkeley on the Representation of Reality Idealism, immaterialism Rejection of the concept of “matter” Argument from the mental dependency of ideas Berkeley thought Locke’s representative realism was dangerous Materialism leads to atheism All ideas, including primary qualities, are ultimately subjective Objectivity is preserved by God as a cause of all our ideas

David Hume Empiricism Principles of Induction Uniformity of nature

An Enquiry Concerning Human Understanding We cannot know that there is an external world. -Impressions are always internal to our experience Hume does not deny that the external world exists, only that we can know it Fundamental beliefs rest on psychological habits, beyond the proof of logic and experience

An Enquiry Concerning Human Understanding Radical implications of empiricism: rejection of matter, cause and effect, and the self The principle of induction and Cause and effect questioned constantly conjoined events Habit Uniformity of nature questioned Circular reasoning of induction Rejection of any knowledge of the ‘self’

Contemporary debate between empiricism and rationalism Nativism and human nature Difference between cognitive capacities and innate content Can the mind have ideas of which it is unaware? Different accounts of which ideas are innate?

Kantian Constuctivism Kant’s agenda Synthetic a posteriori knowledge Synthetic a priori knowledge Critique of Pure Reason: A compromise? -rationalism -empiricism

Kant’s Solution “There can be no doubt that all our knowledge begins with experience…But though our knowledge begins with experience, it does not follow that it all arises out of experience.” “thoughts without content are empty, intuitions without concepts are blind.”

Kant’s Revolution Copernican revolution: from geocentric to heliocentric universe Kantian revolution: from “knowledge conforms to objects” to “objects conform to knowledge” Phenomena and noumena Categories of the mind: space and time

Categories of the Understanding Sensibility Understanding For Kant, categories of the mind structure understanding

What is “Reality” Like and what can we know about it? Phenomenal: The world of possible experience We can know this world so long as we recognize that knowledge of phenomena implies knowledge of ourselves and how we order our experience. Noumenal: The world as it exists “in itself” and independent of any experience of it We Can’t know reality “in itself” because our minds always and unavoidably structure our experience of reality We can’t know the essential or unconditioned nature of the world or even ourselves. Universal forms and categories govern this structuring