Epistemology is the branch of philosophy that investigates the nature, sources, limits, structure, and justification of knowledge.
I. The Two Central Categories / Questions of Epistemology
1. The Nature of Knowledge (“What is knowledge?”)
This category asks: What counts as knowledge?
The Traditional Definition: Justified True Belief (JTB)
A belief counts as knowledge if it satisfies:
- Belief – One must believe the proposition (you can’t know something you don’t believe).
- Truth – The proposition must be true (you can’t know something false).
- Justification – One must have good reasons or evidence for the belief.
Example: If you believe it’s raining, and it really is raining, and you have strong evidence (e.g., you see it and feel it), then your belief qualifies as knowledge under JTB.
Challenge to JTB: The Gettier Problem (1963)
Edmund Gettier presented cases where someone had a justified true belief that still intuitively wasn’t knowledge due to luck.
Example: You look at a clock showing 3:00. It is actually 3:00, and you believe it. But the clock stopped working 12 hours ago. You got lucky—your belief was true and justified, but it doesn’t seem to be knowledge.
Responses to the Gettier Problem:
- Add a “no false lemmas” condition (the belief must not be inferred from any falsehood).
- Require reliability (see reliabilism).
- Add safety or anti-luck conditions.
- Adopt a completely different theory of knowledge (e.g., virtue epistemology or externalism).
2. The Extent of Our Knowledge (“How much can we know?”)
This category addresses skepticism and the limits of what humans can know.
Key Skeptical Questions:
- Can we know anything at all with certainty?
- Are our senses and reasoning reliable?
- Is the external world real or an illusion?
- How do we know that we’re not dreaming, deceived by an evil demon (Descartes), or living in a simulation?
Varieties of Skepticism:
- Global Skepticism: We can’t know anything.
- Local Skepticism: We can’t know certain kinds of things (e.g., metaphysics, morality, the future).
- Methodological Skepticism: Doubt as a tool to find certainty (e.g., Descartes’ method of doubt).
Summary
(1) What is the nature of knowledge?
- What does it mean to “know” something?
- What are the necessary conditions for knowledge?
(2) What is the extent of our knowledge?
- How much can we really know?
- Are there limits to knowledge (e.g., metaphysical, theological, moral truths)?
These questions drive all epistemological inquiry.
II. Kinds of Knowledge
1. Propositional Knowledge (“knowledge-that”)
- Knowing that something is true.
- Example: “I know that 2+2=4.”
2. Procedural Knowledge (“knowledge-how”)
- Knowing how to do something.
- Example: “I know how to ride a bike.”
3. Experiential Knowledge (“knowledge by acquaintance”)
- Knowledge gained through experience or direct awareness.
- Example: “I know what it feels like to be in love.”
Some traditions, especially in theology or existential philosophy, highlight personal knowledge (knowing a person) as unique and distinct.
II. Sources of Knowledge
1. Rationalism
- Knowledge is gained primarily through reason and intellect.
- Emphasizes a priori truths (independent of experience).
- Key figures: Descartes, Leibniz, Spinoza.
2. Empiricism
- All knowledge comes from sense experience.
- Emphasizes a posteriori knowledge (based on observation).
- Key figures: Locke, Berkeley, Hume.
3. Intuitionism
- Some knowledge is immediate or self-evident, needing no reasoning.
- Common in ethics and mathematics.
4. Testimony
- Much knowledge comes from the reports of others (books, teachers, news).
- Raises questions about trust and credibility.
5. Revelation
- In theology, divine revelation (e.g., Scripture) is proposed as a distinct source of knowledge.
6. Constructivism
- Knowledge is constructed by the knower, not merely discovered.
- Associated with Kant and some modern epistemologies.
Each source can be questioned:
- Is perception reliable?
- Is reason trustworthy?
- Can intuition be wrong?
III. Core Epistemological Issues
A. The Criterion Problem (Meno’s Paradox)
Also called: The Problem of the Criterion (most famously raised by Sextus Empiricus and later Roderick Chisholm)
The Core Question:
How do we know what we know?
But also: How do we determine what counts as knowledge (the criterion), and how do we apply that to specific cases?
The Dilemma:
To determine whether a belief is knowledge, we need:
- A criterion: a standard for what counts as knowledge.
- Examples of known instances to help us discover the right criterion.
But here’s the problem:
- We can’t choose the right criterion without already knowing which beliefs are true knowledge.
- But we can’t know which beliefs count as knowledge without already having the right criterion.
Three classic responses:
- Methodism – Start with a method/criterion and use it to identify knowledge.
- (e.g., Empiricism: “Only sense data counts.”)
- Particularism – Start with examples of things we think we know and use those to develop a criterion.
- (e.g., “I know that I have hands, so what lets me know this?”)
- Skepticism – Claim that since we can’t establish either first, we can’t know anything.
Summary:
The criterion problem is about the circular dependency between knowing what knowledge is (the standard) and knowing which beliefs are knowledge (the examples). It’s a meta-epistemological problem—how we even begin to identify knowledge in the first place.
B. The Justification Problem
The Core Question:
What justifies our beliefs, and how is that justification structured?
This is more internal to belief systems. It assumes you have beliefs, and now you’re trying to show why those beliefs are rational or warranted.
The Regress Problem:
- To justify belief A, you need belief B.
- But B also needs justification—say, C.
- And C needs D… and so on.
This leads to:- Infinite regress (which is impossible to complete)
- Circularity (A is justified by B which is justified by A; which is a potential fallacy)
- Arbitrary stopping point (dogmatism)
Responses:
- Foundationalism: Some beliefs are basic and self-justified (e.g., “I exist”).
- Coherentism: Beliefs are justified by how well they cohere in a system.
- Infinitism: There is an infinite chain of reasons, and that’s okay.
- Externalism: Justification doesn’t require internal awareness; a reliable process suffices.
Summary:
The justification problem is about how belief systems are supported and made rational. It is primarily about the structure of justification within a system.
VI. Epistemology and Worldview Analysis
In the context of worldview discussions (like Transcendental Worldview Analysis), epistemology is foundational because:
- It determines how we know anything about reality, morality, God, or truth.
- A worldview must provide a coherent account of knowledge—its possibility, justification, and reliability.
- Key questions include:
- Are laws of logic real, immaterial, and knowable?
- Is truth absolute and knowable?
- Are human cognitive faculties reliable? If so, why?
VII. Epistemological Questions to Test a Worldview
- What is knowledge?
- How do you know what you know?
- What justifies your beliefs?
- Can you know anything for certain?
- Are there truths you can know apart from sensory experience?
- Are your cognitive faculties trustworthy? Why?
- Can a naturalistic worldview account for abstract knowledge (e.g., logic, mathematics)?
- Is knowledge objective or relative?
- What role does divine revelation play, if any?