Epistemology and Knowledge

On Knowledge

Epistemology

• Epistemology is a branch of philosophy that addresses:
  • The definition of knowledge.
  • The scope of knowledge.
  • The criteria for assessing knowledge and knowledge claims, including:
    • Inferential knowledge.
    • Experiential knowledge.

Three Senses of 'Knowledge'

• Knowledge [BLANK], e.g., [BLANK].
• Knowledge [BLANK], e.g., [BLANK].
• Knowledge [BLANK] ([BLANK] [BLANK] [BLANK] [BLANK]), e.g., [BLANK].

Two Philosophical Traditions on Knowledge

Platonic-Cartesian-Anglo-American Tradition

• Views knowledge as a problem, especially concerning skepticism.
• Key questions:
  • What is knowledge?
  • Do we know anything at all?

Aristotelian Tradition

• Treats the existence of knowledge as a fundamental given.
• Key questions:
  • What are the different kinds of knowledge?
  • What are the intellectual virtues, and how do we acquire them?

Traditional Definition of Knowledge

• [This section is a placeholder for the traditional definition of knowledge 'that'.]

Belief

• Belief, Sense #1: Thinking that a proposition is true.
• Belief, Sense #2: As a synonym for faith.
• Philosophical usage of 'belief' typically refers to sense #1 when discussing knowledge 'that'.

Sources of Belief/Truth/Knowledge

• [This section refers to questions related to various sources of belief, truth, and knowledge as discussed in the source material.]

Three Powers of Reason or Intellect

• Apprehension: The power to discern what something is.
• Judgment: The power to form a belief or a sentence consciously.
• Reasoning: The power to infer from other beliefs or sentences.

Illustrative Example

• Identifying Dr. Brown (apprehension).
• Formulating a statement about Dr. Brown (judgment).
• Drawing a valid inference from two statements about Dr. Brown (reasoning).

Additional Sources of Truth

• [This section is for listing, explaining, and providing examples of sources of truth beyond those mentioned by Creel, if any.]

Internal Senses

• Memory
• Imagination
• The universal sense

Universal Sense Illustration

• Comparison of blind patients, fully functioning patients, and blind sight patients in their ability to perceive colors and shapes.

The Desire for More Than Just Truth

• Creel: We want truth in a special way because all means of obtaining truth can also lead to error.

Knowledge vs. Hope

• Assumptions:
  • If I know I did well, I am certain I did well.
  • If I hope I did well, I am not certain I did well.
  • If I know I did well, it is true I did well.
  • If I hope I did well, it may not be true.
• Conclusion: Knowing and hoping are different.
• A good definition requires the definiendum and definiens to be logically equivalent.
• Therefore, defining knowledge as hope is not a good definition.

Faith and Knowledge

Creel on Faith and Knowledge

Deeper Exploration

• Four different senses of faith.
• A general schema for believing by faith.
• Augustine on the ubiquity of believing by faith.
• Hypothesis: Faith can be a form of knowledge 'that', but not the only kind.

Knowledge vs. Faith (Creel's Hypothesis)

• If I know something, I necessarily believe it.
• If I have faith that something is true, I necessarily believe it.
• Therefore, knowledge and faith are similar.
• If I know something, it is true.
• If I have faith, it may not be true.
• Therefore, knowledge and faith differ.
• A good definition requires logical equivalence between the defined and the definition.
• Therefore, knowledge is not adequately defined as faith.

Four Senses of 'Faith'

• Faith in: Trusting someone’s character or competence.
  • Example: Susan trusts Jim because she has faith in him.
• Faith that someone is (or was) [BLANK]: Believing strongly in someone's existence or reality based on:
  • Personal experience, without intellectual certainty.
  • Testimony of others.
  • Example: Faith that God is real; faith that Julius Caesar existed.
• Faith that someone reveals that p: Believing that someone reveals that proposition p based on:
  • Personal experiences without intellectual certainty.
  • Testimony of others.
  • Example: Faith that God inspires scripture; Johnny’s faith that his great-grandmother wrote a book because his mother said so.
• Faith [BLANK] [BLANK] someone [BLANK] is true: [Refer to slide 22 for the complete definition.]

General Schema for Believing by Faith

• Person R believes person S reveals that p.
  • Example: Jasmine believes Jane said she grew up in Bakersfield, CA.
• Person R believes person S is a reliable authority on p.
  • Example: Jasmine believes Jane is reliable about where she grew up.
• Person R believes what S says is true, based on the above.
  • Example: Jasmine believes Jane grew up in Bakersfield because Jane said so, and Jasmine trusts Jane's reliability.
• Jasmine’s belief is a kind of faith 'that' what someone reveals is true.

Aquinas on Human vs. Divine Faith

Human Faith

1. John believes Jasmine reveals 'I went to school in Dresden'.
2. John has faith in Jasmine as a reliable authority.
3. John has faith that Jasmine went to school in Dresden, based on the above.

Divine Faith

1. Dante believes by divine faith that God reveals the Trinity through Scripture.
2. Dante believes God is a perfectly reliable authority who cannot deceive or be deceived.
3. Dante has faith that the Trinity is true, based on the above.

Aquinas on Faith and Knowledge Types

Knowledge by Divine Faith vs. Other Means (Aquinas)

Divine Faith Example

• If Seraphina knows 'Jesus is the Son of God' by divine faith:
  • She believes it.
  • Through an act of will.
  • Responsive to God’s grace.
  • Because she believes God reveals it.
• Seraphina doesn't see it so clearly that she couldn't choose not to believe; she believes primarily because she has faith that God knows and reveals it, typically through the Church.

Knowledge by Other Means

• Belief based on:
  • Trusting human authority without God’s grace.
  • Clear evidence to one's own intellect.
  • Examples: perception, memory, inference from known propositions.
  • Seraphina does not choose to believe; the evidence compels belief.

Creel on Non-Faith Knowledge

• Is knowledge belief based on evidence?
• The John's trial counter example

Philosophical Methods

• Conceptual analysis
• Deductive argument
• Falsifying a hypothesis by thought experiment or counter-example

Falsifying a Hypothesis

• Hypothesis H: Knowledge is belief based on evidence.
• To falsify H: Provide an example where someone believes something and has evidence for it, but does not know it.

Counter-Example: Sally and John

• If knowledge is belief based on evidence, then if Sally believes p based on evidence, Sally knows p.
• Sally believes John is guilty and has evidence, but John is not guilty.
• Knowing p entails believing truly that p.
• Therefore, Sally does not know John is guilty, even with evidence.
• Therefore, it is false that knowledge is belief based on evidence.

Is Knowledge True Belief?

• The Judah example demonstrates this.

Is Knowledge True Belief Based on Evidence?

• The 5th-century Pythagorean argument.

Heliocentrism Argument

• If the sun is divine, planets revolve around it.
• The sun is a divine being.
• Therefore, planets revolve around the sun.

Is Knowledge Justified Belief?

• [This section explores whether knowledge can be defined as justified belief.]

Definitions of 'Justification'

• Strong Evidence: John is justified in believing 'God exists' if he has strong evidence.
• Reasonable Belief: John is justified if his evidence makes it reasonable to believe.

Is Knowledge Justified True Belief?

• [This section considers whether knowledge can be adequately defined as justified true belief.]

The Gettier Problem

• The Mike and Joe Gettier counter-example challenges the JTB theory of knowledge.

Characters

• Mike sees a person walking past Joe’s room.
• Joe is taking a class in paper mache modeling.

Epistemology After Gettier

• Two general approaches to defining knowledge after Gettier
• An example of the justification approach: knowledge as conclusively justified true belief
• The problem of the brain in the vat, the CJTB theory, knowledge, and skepticism
• A different approach after Gettier: causal or externalist theories of knowledge

Two Approaches Post-Gettier

• Justification approach: knowledge = x + justified true belief.
• Causal theory approach: knowledge = true belief [BLANK] in the right way.

Causal Theories of Knowledge

• Joe knows that p iff (a) Joe believes p, (b) p is true + (c) Joe’s belief that p is [BLANK].

The Conclusive Justification Account of Knowledge (CJTB)

• Joe knows that p iff:
  • Joe believes that p.
  • p is true.
  • Joe has conclusive justification (strong evidence E) that p.
  • Joe understands how E provides [BLANK] [BLANK] that p.

Conclusive Justification Defined

• Joe is conclusively justified in believing p if his evidence makes it impossible for him to be mistaken.

Skepticism and the Brain in a Vat

• A Problematic Implication of the CJTB theory: the Brain in the Vat
• Brain in the Vat Thought Experiment and Skepticism about Knowledge

Skepticism Argument

1. If CJTB is correct, knowledge requires absolute certainty.
2. We can’t be absolutely certain we are not brains in vats..
3. If we can’t be sure we are not brains in vats we can't be certain of anything.
4. Therefore, we can’t be absolutely certain of anything.
5. If CJTB is correct, we don’t know anything.
6. The conclusive justification theory of knowledge is correct.
7. Therefore, we don’t know (much of) anything.

Responding to Gettier with CJTB

• JTB predicts knowledge in Gettier cases, but we intuitively feel there is no knowledge.
• Therefore, Gettier cases are counter-examples to JTB.
• CJTB makes the right prediction (no knowledge), but at what cost?

Can we define knowledge without leading to skepticism?

• [This section considers whether it is possible to define knowledge in a way that avoids skepticism.]

Causal Theories of Knowledge

Goldmanian Causal Theory

• Joe knows p iff p is true and p’s being true is causally connected [BLANK] to Joe’s belief that p.
• Externalist (rather than internalist) theories of knowledge
• Examples:
  • The sun is shining causing Joan to believe it.
  • Gary's belief about hypotenuse length based on Pythagorean theorem.
  • John’s belief about rain in Martin caused by Jane's phone call.
• Addresses Gettier cases by focusing on causal connections.
• Advantage over CTJB: handles the John and It’s Raining in Martin case better.
• The Blow to the Head Cases and “the appropriate way” clause.
• The Trudy/Judy Case as a problem for Goldman’s theory.

Alvin Plantinga’s Causal Theory

• Warrant and Proper Function.
• Illustrating proper function theory.
• Plantinga’s core description of knowledge
• Plantinga’s theory and the Trudy/Judy case

Causal Connection Examples

Example 1: Sun is Shining

• The sun's shining causes Joan to believe 'the sun is shining' through her visual perception.

Example 2: Pythagorean Theorem

• Gary believes the hypotenuse of triangle T is 50 meters based on these cascaded beliefs:
• Gary’s believing the hypotenuse of a particular right triangle T is 50 meter long ^ |
  • Gary's measurement of sides, knowledge of the Pythagorean theorem, and calculation.

Example 3: Raining in Martin

• John believes it is raining in Martin because Jane told him, Jane believes it because she sees it.

Internalism vs. Externalism

Internalism

• Requires inspecting one’s reasons for belief.
• Epistemic access requirement: John knows p only if he has reasons and understands why they show p is true.

Externalism

• Rejects internalism; not all knowledge requires conscious access to reasons.
• Examples: Knowing the sun is shining or a geologist knowing the earth's age.

The Importance of the “In the Appropriate Way” Clause

The Blow to the Head Cases

Jones: The appropriate way

• Jones falls down the stairs after tripping and believes the fact that he fell down the stairs
• A minute later, Jones remembers that he just fell down the stairs ^ |
• Jones falls down the stairs

Smith: Not in the appropriate way

• A minute later, Smith believes wolves are snakes, iceberg lettuce is the most flavorful of all foods, and that he just fell down the stairs. ^ |
• Smith has a brain lesion ^ |
• Smith falls down the stairs

Gettier Cases and Goldman's Theories

• In Gettier cases, Goldman’s theories see that causal connections matter.
• Mike believes Joe is in the room because of a paper mache model, not because Joe is actually in the room.

The John and It’s Raining in Martin Case

• Advantage for Goldman's theory as causal connection is present from someone seeing the rain and John believing in it.

The Luck Objection

• If someone simply gets lucky in having a true belief, they do not have knowledge.
• If a theory predicts knowledge in a case of luck, it is flawed.

Alvin Plantinga’s Warrant and Proper Function

• Joe knows that p iff Joe believes that p, p is true and Joe is warranted in believing that p.
• Joe is warranted in believing that p iff
  • Joe’s belief that p is produced by properly functioning cognitive faculties, i.e., not subject to disease or dis-function,
  • where those faculties are operating in an environment or set of circumstances consistent with the design plan of God and/or nature such that
  • the function or purpose of the faculties in question is the production of true beliefs, and
  • the faculties in question successfully produce true beliefs.

Illustrating Proper Function Theory

Joe and Jane

• Joe is blind and in a room where Jane is giving a lecture. Joe believes Jane is in the room and this belief is produced by cognitive faculties, e.g., his hearing Jane, that are functioning properly and successfully, in the sort of environment in which those faculties were designed to operate, according to a design plan the purpose of which is to produce true beliefs. Is Joe’s belief warranted? Does he know Jane is in the room according to Plantinga?

Mike

• Mike (who is blind) believes there is a woman in the room. There is a woman in the room speaking to him. However, his belief that there is a woman in the room is caused by a brain tumor and not by his properly functioning cognitive faculties. Does Mike know there is a woman in the room according to Plantinga? Why or why not?

John

• John believes he hears his father calling from three miles away (although human hearing, at best, can pick up sounds from about a mile away). His father is calling from three miles away. Does John know he hears his father calling from three miles away according to Plantinga?

The Trudy/Judy Case

• Illustrates a problem for Goldman’s theory but is addressed by Plantinga’s.
• Smith sees Trudy but could have easily seen her identical twin Judy; Plantinga’s theory accounts for the lack of warrant due to the unreliable nature of the belief-forming process.

John's father

• John’s father apparently abandoned his family when he was a young boy. When John is sixteen, he strongly believes his father is clandestinely supporting and helping his family (let us say) simply because John has a cognitive faculty that naturally causes him to do so (call that faculty, the power of wish fulfillment), but the purpose of this faculty is not the production of true beliefs; rather, the cognitive faculty naturally produces beliefs that help a human being such as John cope with the cold, cruel environment in which John lives. Is John warranted in so believing?

Leo

• Leo believes the Cardinals won because he has been given a faculty to close his eyes and intuit whether the Cardinals won any given game by an infant deity, which said faculty is designed by such a deity to function in the environment Leo is in. The purpose of the faculty is to produce true beliefs. The faculty is functioning properly. Unfortunately, this infant deity did a poor job designing Leo’s whether-the-Cardinals-won-a-game-intuiting- faculty. When it comes to intuiting whether the Cardinals won, Leo usually gets it wrong. (He would be better off guessing!)

Other Philosophical Methods

• Conceptual analysis
• Deductive argument
• Falsifying a hypothesis by counter-example.
• Inference to the best explanation.

Evaluating Theories of Knowledge