Belief Is Not Knowledge

You look outside and believe:

it is raining.

Maybe you are right.

Maybe a sprinkler is hitting the window.

Belief can be:

• true,
• false,
• justified,
• unjustified.

Knowledge is more demanding.

The Fundamental Distinction

To believe P is:

to take P to be true.

To know P is:

to stand in a stronger epistemic relation to P.

Exactly what stronger relation is required is the central problem of epistemology.

False Belief

You can believe:

the capital of Australia is Sydney.

That belief is false.

Therefore it is not knowledge.

Truth is necessary.

True Belief

Suppose you guess:

the coin will land heads.

It does.

Your belief was true.

Did you know?

No.

True belief alone is not enough.

Lucky Truth

A belief can be true by accident.

Knowledge seems incompatible with excessive epistemic luck.

This becomes central in the Gettier problem.

Classical Analysis

A traditional account says knowledge is:

justified true belief.

Formally:

S knows P if:

1. P is true,
2. S believes P,
3. S is justified in believing P.

This is the JTB model.

Why Belief Is Required

Can you know something you do not believe?

Suppose evidence overwhelmingly supports P, but you insist:

“I do not think P is true.”

It seems strange to say you know P.

Knowledge normally includes belief.

Why Truth Is Required

You cannot know a false proposition.

You may think you know it.

But if P is false:

knowledge fails.

This is a factive property.

Factivity

Knowledge is factive.

If:

S knows P,

then:

P.

Belief is not factive.

Why Justification Is Required

A lucky guess should not count as knowledge.

Justification connects belief to:

• evidence,
• reasons,
• reliable methods.

It distinguishes knowing from accidental correctness.

Example

You check a reliable thermometer.

It reads:

20°C.

You believe:

the room is 20°C.

If the device works normally, the belief appears justified.

But How Much Justification?

Do you need certainty?

Probably not.

Ordinary knowledge is fallible.

You can know something even though error remains possible.

Fallibilism

Fallibilism says knowledge does not require absolute certainty.

A belief can be well justified and still, in principle, mistaken.

This reflects scientific practice.

Infallibilism

An infallibilist requires stronger certainty.

This creates skepticism about ordinary knowledge.

Few everyday beliefs meet such a standard.

Knowledge vs Certainty

You can know:

your car is parked outside

without being certain beyond all conceivable doubt.

Knowledge and certainty should not be conflated.

Evidence

What counts as justification?

Possible sources include:

• perception,
• memory,
• testimony,
• inference.

Each can fail.

Epistemology studies when they are reliable enough.

Perceptual Knowledge

You see a tree.

Under normal conditions, this justifies:

there is a tree.

But hallucination is possible.

Do you still know?

Fallibilists say yes if conditions are appropriate.

Skeptical Possibility

What if you are dreaming?

What if you are in a simulation?

If knowledge requires ruling out every logical possibility, ordinary knowledge collapses.

This motivates contextualism and fallibilism.

Contextual Standards

In ordinary conversation, evidence may be sufficient.

In a courtroom or philosophical discussion, stronger evidence may be demanded.

Knowledge attributions can be context-sensitive.

Memory Knowledge

You remember:

you had breakfast.

Memory usually justifies belief.

But memory can be:

• distorted,
• false.

Reliability matters.

Testimonial Knowledge

You know:

Tokyo is in Japan

largely through testimony and education.

Knowledge does not require direct observation.

Social transmission is essential.

Expert Knowledge

You may know a medical fact because a reliable expert tells you.

This depends on:

• expertise,
• trust.

Knowing whom to trust becomes epistemically important.

Inference

You know:

the streets are wet.

You infer:

it probably rained.

Inference can extend knowledge beyond direct observation.

But the conclusion may be wrong.

Deductive Knowledge

If you know:

all humans are mortal

and:

Socrates is human,

you can infer:

Socrates is mortal.

Valid deduction preserves truth if premises are true.

Inductive Knowledge

Much scientific knowledge is inductive.

It is supported by:

• repeated evidence,
• statistical inference.

It is not deductively certain.

Knowledge and Probability

Could knowledge simply be:

very high probability?

Not obviously.

You can be 99.999% confident a lottery ticket will lose and still hesitate to say you know it will lose.

Lottery Problem

Suppose one million tickets exist.

For any particular ticket, losing probability is:

0.999999.

Yet before the draw, we usually do not say:

“I know ticket 537 will lose.”

Probability alone does not capture knowledge.

Safety

One proposed condition is safety.

Roughly:

a belief is safe if in nearby possible situations where you form it in the same way, it would not easily be false.

This tries to reduce epistemic luck.

Sensitivity

Another idea is sensitivity:

If P were false, would you still believe P?

If yes, the belief may be epistemically defective.

This has influenced externalist theories.

Reliabilism

Reliabilism says a belief is justified or knowledgeable if produced by a reliable process.

Examples:

• normal vision,
• competent measurement.

The subject need not know why the process is reliable.

Internalism

Epistemic internalism says justification depends on reasons accessible to the subject.

You should be able, in some sense, to justify your belief from within your perspective.

Externalism

Epistemic externalism allows factors outside conscious access.

A reliable process can produce knowledge even if the person cannot articulate the justification.

Chicken Sexers

A classic example involves experts who reliably distinguish chick sex but cannot explain how.

If the process is reliable, do they know?

Externalists are more comfortable saying yes.

Clairvoyant Problem

Suppose someone has a perfectly reliable but inexplicable clairvoyant faculty.

Would resulting beliefs count as knowledge?

This tests externalist intuitions.

Knowledge by Luck

The deepest issue is not merely justification.

A belief can satisfy:

• truth,
• belief,
• apparent justification

and still be true accidentally.

This is exactly what Gettier exposed.

Knowledge-How

Not all knowledge is propositional.

You may know:

how to ride a bicycle

without being able to state every rule.

This is knowledge-how.

Knowledge-That

Knowing:

that Paris is in France

is propositional knowledge.

The distinction is associated with Gilbert Ryle.

Acquaintance Knowledge

You may know:

a person, a place, a sensation

through direct acquaintance.

This differs from knowing propositions about them.

Knowing Red

Mary’s Room raised this issue.

Knowing every fact about color may differ from:

knowing what red looks like.

Different epistemic relations exist.

Knowledge and Understanding

You can know many isolated facts without understanding the system.

Understanding involves:

• relations,
• explanations.

Knowledge is not the highest epistemic state.

Knowledge and Wisdom

Wisdom includes good judgment about:

• what matters,
• how to act.

A person can possess enormous knowledge without wisdom.

Collective Knowledge

Organizations can possess knowledge distributed across:

• people,
• records.

No single person may hold it all.

Knowledge can be systemic.

Scientific Knowledge

Science does not require certainty.

It builds:

• justified,
• testable,
• revisable beliefs.

Scientific knowledge remains provisional yet strong.

Revision

A belief can count as knowledge today and later be revised if evidence changes.

Does that mean it was never knowledge?

Not necessarily under fallibilism.

Epistemic status depends on available justification.

Defeaters

New evidence can defeat justification.

Suppose you see a barn.

Then learn the area is full of fake barn facades.

Your confidence should change.

Defeater

A defeater is information that undermines:

• evidence,
• reliability.

Knowledge requires absence of relevant undefeated defeaters.

Epistemic Responsibility

People have duties such as:

• check evidence,
• avoid careless belief.

But responsibility does not guarantee truth.

A careful person can still be wrong.

Belief Is Psychologically Easy

You can form a belief through:

• rumor,
• emotion.

Knowledge requires epistemic discipline.

That is why the two concepts should never be merged.

The Philosophical Lesson

Belief means:

taking something to be true.

Knowledge requires at least:

• belief,
• truth,
• epistemic support.

But even justified true belief may fail.

A belief can be justified and true yet still be true in the wrong way.

The Next Question

In 1963, Edmund Gettier showed this with remarkably short counterexamples.

His cases changed epistemology.

The next essay asks:

Why is justified true belief not enough?

That is:

The Gettier Problem.