Class notes on Locke

(Originally written March 15, 2006 in 3 Subject)

History of Philosophy II

Locke

Knowledge & the external world

-Our existence is known by introspections or reflection
-God's existence is known through reason
-Physical objects are known by sensations

Why can we trust our senses?

1) Those who lack a sense also lack its ideas.
-Problem: This argument assumes that the external world exists when it is trying to prove that the external world exists. (It assumes that people who lack a sense exist)

2) Some ideas are unavoidable, that is they are not in the control of the will.
-Problems: There could be a hidden faculty or unknown in us, that produces these thoughts.

3) Many painful ideas are remembered without the pain.
-Problems: This is also true in dreams and in hallucinations.

4)Intersensory confirmation. We can see, smell, touch, taste and hear the same physical objects.
-Problems: 1) Dreams can produce the same effects. 2) Berkeley - Heterogenity of the senses

Solipsism - only I exist and thus, the external world is a product of my ideas (metaphysical version)

Solipsism - only I and my thoughts can be known to me (epistemological version)

You cannot notice a working clock that is digital or turn off or on the light switch in dreams.

Hobbes to Hume (Page 252, Locke)

3 Degrees of Cognitive Adequacy:

1) Intuitive knowledge (single intuition) - immediate certainty, the mind sees the necessary connection

2) Demonstrative knowledge (chain of intuitions) - "less easy" or "less clear" than intuitive knowledge. The immediate connection is not seen; the connections is seen by seeing subconnections (which are seen immediately)

3) Sensitive knowledge - no connection is seen. Locke & Descartes define knowledge as "clear and distinct apprehension of a necessary relation" and as such, Locke calls all sensitive knowledge opinion or faith

The objective of knowledge:

The mind knows nothing but itself and what is in it. "Knowledge then seems to me be to be nothing but the perception of the connection and agreement or disagreement and repugnancy of any of our ideas" (Jones, 253).

Locke side steps the problem of our ideas matching up with reality and simply assumes that they do.

Knowledge of real existence:

3 Real existents:
-selves
-God
-bodies

1) Of the self, one has intuitive knowledge
2) Of God, one has a demonstrative knowledge
3) of other selves and physical objects one has only sensitive knowledge (which are opinions and faith)

Of other selves and physical objects two questions arise:
1) Do they exist while we experience them?
2) Do they exists while we do not experience them?

Locke's Answers
1) "What we see and feel cannot be demonstrated, but nobody can in earnest be so skeptical as to be uncertain" (Jones, 255)
2) It is "highly probable" that they do exist when we do not experience them.

Bodies in motion (in reality) cover two kinds of ideas in us:
1) Ideas that truly resemble existence, i.e. solidity, extensions, figure and mobility (primary qualities of a body)
2) Ideas that do not resemble existence, i.e. sweet, red

Locke denied that essences can be known, but affirmed there existence. His critics then asked how Locke knew that they truly existed.

Knowledge of relations:

Men bring two ideas together without uniting them to view them at the same time. Thus, agreements and disagreements are found between them. There are two types of agreements/disagreements that are most important:
1) Identity and diversity
2) Coexistence

"Blue is not yellow" is an example of identity and diversity. This knowledge is basic. By knowing that blue is blue one knows that blue is not-yellow.

"Iron is susceptible of magnetic attraction" is an example of coexistence. These agreements/disagreements are a set of secondary qualities. All of iron's qualities coexist to form the complex idea of iron. Continental rationalists' science, as being demonstratively certain prepositions is only possible because the Continental rationalists assumed they know the true essences of things. They thought they knew the true essences of things because they were confused about the state of names.

Names:

A name is a device to "abridge discourse". It stands for:
1) a group of coexisting ideas or
2) on of such a coexisting group "apple" is a name for the idea of a "red-spherical-sweet"

"Abstract ideas" are names that we give to ideas that have been isolated or abstracted from its context