Overview
The question "What is knowledge?" is central to epistemology and affects virtually every area of human inquiry. Understanding the nature of knowledge helps us evaluate claims, assess evidence, and determine what we can legitimately believe.
Why This Question Matters
- Distinguishes knowledge from mere opinion or belief
- Provides criteria for evaluating truth claims
- Underlies scientific methodology and reasoning
- Affects religious, moral, and political discourse
How do we distinguish between genuine knowledge and beliefs that merely happen to be true? What transforms true belief into knowledge?
Historical Importance
Philosophers have grappled with defining knowledge for over 2,500 years, from ancient Greece to contemporary epistemology. The question remains active and contested in modern philosophy.
The Traditional Definition
The classical definition of knowledge, traceable to Plato, holds that knowledge is "justified true belief" (JTB).
The Three Components
1. p is true (Truth condition)
2. S believes that p (Belief condition)
3. S is justified in believing that p (Justification condition)
Explanation of Each Condition
Truth Condition
- Knowledge requires that the believed proposition actually be true
- Cannot have knowledge of false propositions
- Distinguishes knowledge from mere belief
- Raises questions about the nature of truth itself
Belief Condition
- Must actually believe the proposition in question
- Cannot know something without believing it
- Belief involves mental assent or acceptance
- Distinguishes knowledge from mere understanding
Justification Condition
- Must have good reasons or evidence for the belief
- Distinguishes knowledge from lucky guesses
- Involves epistemic responsibility
- Most controversial and complex component
Intuitive Appeal
The JTB definition captures our intuitive understanding that knowledge requires more than just true belief—it requires that the belief be properly grounded in evidence or reasoning.
The Gettier Problem
In 1963, Edmund Gettier published a famous paper showing that justified true belief is not sufficient for knowledge.
Gettier's Original Cases
Smith believes "The man who will get the job has 10 coins in his pocket" based on strong evidence that Jones will get the job and has 10 coins. But Smith actually gets the job and, unknowingly, also has 10 coins. His belief is justified, true, but not knowledge.
Structure of Gettier Cases
- Justified belief: The believer has good evidence
- True conclusion: The believed proposition is actually true
- Lucky connection: The belief is true for reasons other than the justification
- Epistemic luck: The truth is accidental relative to the justification
Modern Gettier Cases
Henry drives through an area with many fake barn facades but happens to look at the one real barn. He has a justified true belief that he's looking at a barn, but this seems like luck rather than knowledge.
The Lesson
Epistemic Luck
Gettier cases show that justified true belief can still involve problematic epistemic luck. Knowledge seems to require that truth and justification be connected in the right way, not merely coincidentally.
Alternative Theories
Philosophers have proposed various solutions to the Gettier problem and alternative theories of knowledge.
Reliabilism
- Knowledge requires beliefs formed by reliable processes
- Focus shifts from internal justification to external reliability
- Perception, memory, and reasoning can be reliable processes
- Avoids some Gettier problems by requiring proper causal connection
Virtue Epistemology
Knowledge results from intellectual virtues like careful observation, critical thinking, intellectual honesty, and open-mindedness. Knowledge is what a virtuous epistemic agent would believe.
Contextualism
- Standards for knowledge vary by context
- What counts as knowledge depends on practical stakes
- Higher standards apply in more important situations
- Resolves apparent conflicts about knowledge attributions
Safety and Sensitivity Conditions
- Safety: In nearby possible worlds, if S believes p, then p is true
- Sensitivity: If p were false, S would not believe p
- These conditions aim to eliminate epistemic luck
- Both face counterexamples and technical challenges
No Consensus
Despite decades of effort, philosophers have not reached consensus on the correct analysis of knowledge. Each proposed theory faces objections and counterexamples.
Types of Knowledge
Philosophers distinguish between different types of knowledge that may require different analyses.
Propositional Knowledge
- Know-that: Knowledge of facts or propositions
- Examples: Knowing that Paris is in France, that 2+2=4
- Features: Can be expressed in language, true or false
- Primary focus: Most epistemological analysis concerns this type
Procedural Knowledge
Knowledge of how to do things, like riding a bicycle, playing piano, or speaking a language. This knowledge is often difficult to articulate and seems different from propositional knowledge.
Acquaintance Knowledge
- Know-of: Direct acquaintance with objects, people, or experiences
- Examples: Knowing Paris (having visited), knowing pain (having felt it)
- Features: Direct, experiential, not reducible to propositions
- Phenomenological: Involves qualitative experience
A Priori vs. A Posteriori
- A priori: Knowledge independent of experience (mathematics, logic)
- A posteriori: Knowledge dependent on experience (empirical facts)
- Debate: Whether this distinction is clear or fundamental
Unified Theory?
Whether all types of knowledge share a common nature or require different analyses remains an open question in contemporary epistemology.
Skeptical Challenges
Skeptics argue that we have little or no knowledge, challenging our most basic epistemic assumptions.
Classic Skeptical Arguments
How do you know you're not a brain in a vat, being fed false sensory experiences? If you can't rule out this possibility, do you really know anything about the external world?
The Regress Problem
- Justification seems to require further justification
- This leads to infinite regress, circularity, or arbitrary stopping points
- None of these options seems satisfactory
- Challenges the possibility of ultimate justification
The Problem of the Criterion
- To know something, we need criteria for knowledge
- But to know the criteria are correct, we need to apply them
- This creates a circular dependency
- How can we bootstrap our way to knowledge?
Responses to Skepticism
- Foundationalism: Some beliefs are self-evident or basic
- Coherentism: Justification comes from coherent belief systems
- Pragmatism: Focus on what works rather than certainty
- Externalism: We don't need access to our justification
Living with Uncertainty
Whether or not skepticism can be definitively refuted, it serves the important function of making us more careful about our epistemic claims and more aware of our cognitive limitations.
Assessment
The question "What is knowledge?" remains one of philosophy's most challenging and important problems.
Current Status
- No universally accepted definition of knowledge
- Multiple competing theories, each with strengths and weaknesses
- Growing recognition that knowledge might be a complex, multi-faceted concept
- Increasing focus on practical and social aspects of knowledge
Practical Implications
- Science: Understanding scientific knowledge and methodology
- Education: Knowing what to teach and how
- Law: Standards of evidence and testimony
- Technology: Artificial intelligence and machine learning
Future Directions
Evolving Field
Contemporary epistemology increasingly incorporates insights from psychology, cognitive science, and sociology, leading to more naturalistic and social approaches to understanding knowledge.
While we may not have a final answer to "What is knowledge?", the pursuit of this question continues to deepen our understanding of truth, belief, justification, and the human condition itself.