Locke, Hume and Kant - WordPress.com · Outline Locke‟s empiricist philosophy 3. Examine Hume‟s empiricist philosophy and its relation to Locke‟s philosophy 4. ... Locke, Hume

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LECTURE 11: LOCKE, HUME AND

KANT

TODAY‟S LECTURE

In Today‟s Lecture we will:

1. Recap our epistemological options

2. Outline Locke‟s empiricist philosophy

3. Examine Hume‟s empiricist philosophy and its relation to Locke‟s

philosophy

4. Discuss Kant‟s contribution to the discussion and his own response to

Hume‟s philosophy

CLASSICAL EMPIRICISM

According to Empiricism:

The mind is a blank slate (tabula rasa)

Knowledge of existing things is „written‟ onto this blank slate through sense

experience

All Knowledge, concepts, universals, and general ideas come from experience

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RATIONALISM

According to Rationalism:

The mind is not a blank slate

Some knowledge is written onto our minds through experience

Some knowledge is already written in our minds at Birth (Gained

independently of experience)

TWO TYPES OF KNOWLEDGE

A Priori

Independent of senses

Universal

Certain

A Posteriori

Derived from sense experience

Specific

Not certain

2+2=4

Oooh there's an

apple!

JOHN LOCKE’S MODERN

EMPIRICISM

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JOHN LOCKE

Introduction

o Lived 1632 – 1704

o An advocate of Empiricism and science

o Employed an Experimental method

o Opposed to rationalist and “overly

philosophical” theories

o Very influential philosophical figure in

the history of the Enlightenment and the

American Revolution

o Has a character named after him in Lost

JOHN LOCKE

Locke‟s Arguments against Rationalism

Locke argues that the theory of innate ideas employed by the rationalists

(such as Plato and Descartes) is incorrect for the following reasons:

A. Rationalists claim that there are certain principles agreed upon by

everyone

1. Universal consent proves nothing innate

2. There is no universal consent

3. If there were universal ideas children and „idiots‟ would possess them

B. Rationalists claim that innate ideas can only be known through the use of

reason

1. Knowledge derived from reason is not necessarily innate

2. Reason is only a faculty of deduction

CLASSICAL EMPIRICISM

According to Empiricism (again):

The mind is a blank slate (tabula rasa)

Knowledge of existing things is „written‟ onto this blank slate through sense

experience

All Knowledge, concepts, universals, and general ideas come from experience

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JOHN LOCKE

Sensation

(External Experience)

Sensations of objects in the

external world

Reflection

(Inner Experience)

Processes of cognition

Locke‟s Theory of Knowledge

There are two forms of experience:

All knowledge is derived from external and internal Experience

JOHN LOCKE

Problem:

How do we arrive at universal ideas on the basis of our limited experience of

particular things?

Locke:

Complex ideas (universals, etc.) are composed of sensations which are

operated on and made complex by our cognitive faculties

JOHN LOCKE

Locke claims that there are two types of ideas:

1. Simple Ideas

“Being in itself uncompounded, contains in it nothing but one uniform

appearance, or conception in the mind (p.280)

Simple ideas are the basic building blocks of all thinking

Examples: Clear, Hard, cold.

2. Complex Ideas

“When the understanding is once stored with these simple ideas, it has the

power to repeat, compare, and unite them, even to an almost infinite variety,

and so can make at pleasure new complex ideas” (p.280)

Complex ideas are made from simple ideas by our intellectual faculties

Examples: Ice, cup, chairs.

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FACULTIES

Locke argues that humans possess the following cognitive faculties:

1. Distinguishing

2. Comparing

3. Together-ing

4. Naming

5. Abstracting

JOHN LOCKE

Abstraction

Our faculty of abstraction allows us to abstract from individual and particular

features and single out essential features

But these universals only apply to words

Particular Features

Plastic, Blue, 10 lb.

Wooden,

Black/Brown, Shiny

Wooden, Black, Shiny

Universal Features

Chair

Used for sitting, four

legs, back support.

JOHN LOCKE

Nominalism

The doctrine that Forms, or Universals, are merely universal names by

which we group together things that possess similar features

o Maintains that Forms and essences (universals) do not have any

independent existences.

o They are just words we use to group things together with similar features.

For example,

There is no such thing as game-ness, chair-ness, etc.

The words are merely a way of categorizing and naming similar things

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JOHN LOCKE

Locke‟s Theory of Knowledge:

All ideas (knowledge) comes from experience

There are two forms of experience:

Sensation (Outer)

Reflection (Inner)

All ideas are either from inner experience or outer experience

There are no innate ideas, only innate faculties

Experience

Sensation Reflection

Simple Ideas

Complex Ideas

Passive

Active

DAVID HUME’S RADICAL

EMPIRICISM

DAVID HUME

David Hume:

o Lived 1711-1776

o One of the „great‟ British empiricists

o Advocated a Radical form of empiricism

o Made important contributions to

Metaphysics, Epistemology, Philosophy

of Religion

o Hume‟s radical empiricism has

important consequences for the

investigation into philosophy, religion

and science

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DAVID HUME

David Hume‟s Phenomenalism

All knowledge is derived from and limited to Experience (appearances)

Hume labels the contents of our consciousness; Perceptions

Perceptions can be divided between:

1. Impressions

Lively, Vivid Sensations

(Anything we are seeing, hearing etc.)

2. Ideas

Pale impressions / copies of impressions

(thinking about something instead of seeing/touching etc.)

All ideas are derived from impressions (no knowledge about the world can

come from reason alone)

All the mind possesses is a collection of perceptions

DAVID HUME

Ideas

Impressions

Perc

ep

tions

Every one will readily allow, that there is a

considerable difference between the

perceptions of the mind, when a man feels

the pain of excessive heat, or the pleasure

of moderate warmth, and when he

afterwards recalls to his memory this

sensation, or anticipates it by his

imagination.

These faculties may mimic or copy the

perceptions of the senses; but they never

can entirely reach the force and vivacity of

the original sentiment.

-David Hume

DAVID HUME

David Hume‟s Phenomenalism

There are two bases of knowledge:

1. Relations of Ideas

Ideas that are intuitively or demonstratively certain

E.g. Geometry, Arithmatic, Logic, Algebra etc.

2. Matters of Fact

Ideas that pertain to the world

E.g. The sun will rise tomorrow, This chair is red, etc.

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DAVID HUME

What‟s so radical about Hume‟s radical empiricism?

Empiricists such as Aristotle, & Locke all argue that we can have certain

knowledge

For example;

This is a chair

The chair is really red

The chair exists

Frogs are green

But! Hume argues that these thinkers fail to follow empiricism to its

rational conclusions

DAVID HUME

Hume: If all knowledge comes from perception

Either

Our knowledge is

1: Certain but not informative

Or

2: Informative but not certain

Or

It is not knowledge;

We have no rational

justification

We may have strong beliefs in things which cannot be seen

But, for Hume such beliefs are not rational

Hence Hume is showing that theories which depend too greatly on

reason are invalid!

IMPLICATIONS OF HUME’S

RADICAL EMPIRICISM

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IMPLICATIONS

The limits of knowledge:

1. Relations of Ideas

Ideas that are intuitively or demonstratively certain

E.g. Geometry, Arithmetic, Logic, Algebra etc.

Relations of ideas can give us certain knowledge

They don‟t teach us anything new

They have no bearing or relevance on reality

For Example:

Socrates is a man

All men are mortal

Therefore Socrates is mortal

Doesn‟t teach us anything new

Has no relevance upon reality

Certain

IMPLICATIONS

The limits of knowledge:

2. Matters of Fact

Ideas that pertain to the world

E.g. The sun will rise tomorrow, This chair is red, etc.

Matters of fact can teach us new things about the world

But they can never be certain

It is always possible that they can be rendered false

Entirely dependent on perceptions

For Example:

Feelings of love can provide

pain relief

Teaches us something new about

the world

Cannot be certain

IMPLICATIONS

Hume‟s attack on the principle of substance:

It is natural to believe:

Descartes/Locke: There exists both mental and physical substance

Hume‟s challenge:

Do we ever perceive substance? No.

Therefore, we cannot rationally claim that substance exists

Hume: Sense impressions have priority over ideas

There are no ideas without sense impressions

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IMPLICATIONS

Hume‟s attack on the principle of the „Self‟:

It is natural to believe:

Descartes: There is a thinking thing, a „self‟, ego, etc.

Hume‟s challenge:

Do we ever perceive a self? No. Only many perceptions

Therefore, we cannot rationally claim that the self exists

Hume: Sense impressions have priority over ideas

There are no ideas without sense impressions

IMPLICATIONS

Hume‟s attack on the principle of „Causality‟:

It is natural to believe:

That every event has a cause / Causal connection

Hume‟s challenge:

Do we ever perceive a necessary connection? No.

We perceive that A occurs, then B occurs;

but we don‟t perceive the necessary connection where A causes B

All we perceive is contiguity (things close together) and succession;

We never perceive causation!

Therefore, we cannot rationally claim that every event has a cause

Hume: Sense impressions have priority over ideas

There are no ideas without sense impressions

IMPLICATIONS

Examples against causation:

At age 1 a child begins to:

o Feed themselves

o Walk by themselves

o Learns simple words

o Receives their Measles, Mumps, Rubella vaccinations

For Example:

A child (A) receives their MMR vaccinations, then (B) begins to feed

themselves

A B

But! A did not cause B.

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IMPLICATIONS

Implications for modern scientists and philosophers:

1. All scientific theories must be limited to what can be observed or observed in

principle

2. All scientific claims are either

i. Relations of ideas

E.g. All mammals are warm blooded

Or

ii. Matters of fact

E.g. The Earth day is now 1.26 nanoseconds faster

3. Scientific claims/‟laws‟/theories cannot be certain (only likely or unlikely)

It is always possible that a scientific claim can be proved false because

of future observations

Popper: Scientific theories must be falsifiable (Principle of Falsifiability)

For example:

Theories of the subconscious cannot be observed or falsified;

therefore they are not scientific

SUMMARY

Summary:

Empirical (all) knowledge can only be either:

Necessarily true but not informative

Or

Informative but not certain

All ideas are derived from perceptions

Any idea we have that is NOT derived from perceptions should be abandoned

When we run over libraries, persuaded of these principles, what havoc

must we make? If we take in our hand any volume, of divinity or

school metaphysics, for instance; let us ask, “Does it contain any

experimental reasoning concerning matter of fact and existence?” No.

Commit it then to the flames: for it can contain nothing but sophistry

and illusion.

(David Hume)

KANT

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IMMANUEL KANT

Outline:

Lived 1724-1804

Represents an important turning point in

epistemology

Wrote the Critique of Pure Reason in response to

Hume‟s radical empiricism

IMMANUEL KANT

Kant maintains the following:

Kant rejects the empiricist claim that the mind is a „blank-slate‟

He also rejects the rationalist claim that we possess innate ideas

Unlike Hume Kant claims we can be certain that:

Every event must have a cause

Substance exists

The self exists

KANT’S THEORY OF KNOWLEDGE

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KANT

A Priori

Independent of Experience

Universal

Certain

A Posteriori

Derived from sense experience

Specific

Uncertain

Analytic

True by definition

Not informative

Synthetic

Informative

Kant‟s understanding of „knowledge‟

KANT

Activity: List any knowledge that corresponds to the following categories:

Synthetic a posteriori Knowledge

The room is red

The moon is 2159 miles in diameter

Analytic a priori knowledge

All bachelors are unmarried men

A triangle is a three sided closed shape

Analytic a posteriori Knowledge

Informative but

not certain

Certain but not

informative

Analytic a posteriori knowledge

is not possible!

KANT

The search for synthetic a priori knowledge

Kant wants knowledge which is certain, not derived from experience, and still

informative

It must be both Synthetic and a priori

Informative, not just

true by definitionNecessary & Universal

For Example:

Every event has a cause

Substance exists

The Self exists

The big question is whether such knowledge exists!

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KANT

Traditional theories of knowledge

Traditional theories of knowledge are concerned with asking whether

our idea of the apple corresponds to the apple itself

KANT

Kant‟s Copernican Revolution

Instead of asking how our knowledge conforms to objects in the world;

Kant asks how objects in the world must conform to us

KANT

Kant‟s theory of knowledge

Synthetic a priori (SAP) knowledge is not derived from experience

SAP is the basis for experience

SAP defines how we experience

Our minds possess innate structures called „categories of the understanding‟

Unity

Plurality

Totality

Relations of substance and characteristics of substance

Relations of cause and effect

Relations of reciprocity

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KANT

Space and Time

Space and Time are both a priori conditions for all experience

ALL objects must be in space and time to be experienced

Kant maintains that space and time are contributed by our minds

We can have no knowledge of an object which is not in space or time

Kant‟s disagreement with Hume:

Hume maintained that belief in the following is irrational:

Causality

The self

Substance

For Kant these concepts are not only certainly true; They must be true!

They are universal and necessary for experience

If they were not true then we would not be able to have experience

KANT

KANT

Summary:

Unlike Hume Kant maintains that we can have knowledge which is both

informative and certain:

Synthetic a priori knowledge

Such knowledge is universal and necessary

Without it experience would not be possible

Kant‟s Copernican revolution makes humans, not the world, the central focus

of epistemology

Our minds create the conditions necessary to experience the world

Space and Time

Categories of the Understanding