From Rationalism to Empiricism


The mood of 17th Century "Enlightenment"

"Reason" stood for:

- "Cool" objectivity vs. "Passion"

- Intellection vs. Revelation

- Impartiality vs. Prejudice

It was implied that:

a) All men have the power to reason

b) All problems can be solved by the

use of reason

Views of "Reason"

Continental British

Rationalist vs. Empiricists

e.g., Descartes, e.g., Locke,Berkeley,

Leibniz, Kant Hume

- - - - - - Emphasis on:- - - - - - - - -

Deductive Inductive

Reasoning Reasoning

Abstract, Fancy "Down-to-

Model Building Earth"

Mathematics Mathematics

Emphasised Not Emphasised

Argument (Logic) Experience as

as criterion of as criterion of

validity: validity:

Rationalism Empiricism


John Locke (1632-1704)

Major work: Essay Concerning Human Understanding

Reference: W.T. Jones: Hobbes to Hume

Trained as a physician with political interests

Implicitly borrowed from Descartes:

- Dualism (Mind-Matter)

- Ideas as (mental)
representations of objects

- Minds know their states: Reflection (introspection)


- Rejected the concept of innate ideas,

which had been attributed to Descartes

- Mind viewed as "Tabula Rasa;"

a clean, empty closet,

rather than one cluttered by

(God-given) "innate" ideas

Locke's theory of the origin of ideas:

- "There is nothing in the intellect

that was not first in the senses."

- Sensory experience is the root

of all ideas {... and of knowledge}

From psychology to epistemology:

- "Only experience can confirm

or dis-confirm beliefs

-- an epistemological doctrine

More on the theory of origin & development of ideas:

- Sensation and Reflection: two sources of ideas


- the main source of ideas

- provides materials for thinking

- represents the relatively passive

mode of the mind


- involves processes/operations

e.g. doubting, reasoning, willing

- represents the active aspect of the mind

- enables having "ideas of ideas"

Simple and Complex ideas:

Simple ideas

- may originate in sensation or reflection

- are incapable of further analysis

e.g. "solidity", which can be

experienced, but not explained

Complex ideas

- arise from simple ideas

--by uniting/combining them

e.g.: rose = pink + soft + moist

--by comparing, and

--by abstracting (teasing out commonality among many)

(Note: Abilities for reflection are native

to the mind, but its contents aren't )

Primary and secondary qualities:

Ideas of primary qualities

- e.g., solidity, figure, motion

- belong to objects themselves

- are independent of the perceiving mind

Ideas of secondary qualities

- e.g. colour, sound, taste, warmth

- are dependent on the perceiving mind

-- "experiment": same lukewarm water

feels hot or cold to cold or warm hands

Note: This "experiment"

1. illustrates Locke's empirical


2. implies that primary qualities are

mind-independent (i.e., "real").

3. Importance of the distinction between ideas of

primary and secondary qualities:

which are respectively

mind-independent & mind-dependent.

It indicates the interest of modern

science in describing the world as it is,

not as it appears to be to an

interpreting mind.

Later on positivists followed this idea by

asking us to restrict to what is

"given in experience", and

disregard what is "added by the mind"

(mainly interpretation)

Locke on person, self and identity

- Being a person implies being a citizen

with rights and responsibilities.

- Understanding, feeling, and (free) will,

i.e., cognition, affect, and conation

(sometimes called the "trilogy of

mind") are necessary psychological

conditions of personhood

- Contrast Hobbes's view of persons as

automata shaped by efficient causes


David Hume (1711-1776)

Important Works: 1738 -A Treatise of Human Nature

1748 -An Inquiry Concerning Human Understanding

Developed empiricist philosophy and psychology

- proposed experience is composed

of impressions and ideas held as distinct,

separate and isolated units (psychological atomism)

Observed that ideas usually follow one another in patterns governed by the

Laws of Association of Ideas:

(1) Resemblance

(2) Contiguity in Space & in Time

(3) Cause & Effect (a corollary of #2)

Note: Cause & effect merely a matter of

association of ideas!

Hume's view of Causality - Recognised the idea of causation as

foundational for science, & that

- causality implies the assumption that

certain kind of events (effects)

must necessarily follow

certain other kinds of events (causes)

- Causal necessity is not

"given in experience"; it is

"added by the mind," which habitually

expects that future events will follow

the "constant conjunction" noted

in the past

- Science is limited to historical

statements, & induction from "some"

to "all" is a matter of a convenient

expectation - Limits of induction!

Note: - Insofar as empiricism suggests

that only experience can confirm

or dis-confirm ideas, then there is

no empirical justification for causality

- Empiricism leads to skepticism, not to certainty!

Hume on will and moral behaviour

- Volition does not produce action any more than causes produce effects

- "Reason is, and ought only to be, the slave of the passions"

Note: Humean empiricism shook the

foundations of science & morality,

inviting Kant's response

Hume on Self Introspective approach:

"I can never catch myself at any time

without a [particular] perception"

Note: - purely empirical approach

(i.e., based on experience)

- self is different each moment

Unity of mind (or self) despite diversity

of its contents (ideas) explained by the

Laws of Association only

There is no "self" that remains one & the same;

mind (self) is a mere bundle of ideas

Hume felt tormented by the implications

his theory of no-self, and left philosophy


Locke & Hume's Legacy for Psychology

1. Empiricism: Reliance on

observation ("data") rather than

argument ("theory")

2. View of the mind (or organism) as

empty: no "nativism" (i.e., no belief

in in-born basis of knowledge)

3 View of knowledge as "copy"

of reality; not reality as active

construction of the mind

4. Emphasis on laws of association

(anticipated laws of learning)

5. Implicit atomism: reliance on bits

of information, not knowledge of

the whole as such.

6. "Lockean Model" of theory building

Theory should begin with simple

concepts and lead to complex ones

gradually, even as our mind

(supposedly) functions (according

to Locke)

7. Notion of person is influential in American

ideology and psychology

Locke was one of the architects of a secular

scientific, liberal viewpoint - co wrote constitution

of Carolina colony with Shatsebury (laissez-faire liberty)

built on good education and individualism