KNOWLEDGE AND ITS DEGREES by JOBISH MADATHIKUZHIYIL (09020)

KNOWLEDGE AND ITS DEGREES

 

 

Having provided a thorough account of the origins of our ideas in experience, Locke opens Book IV of the Essay with a deceptively simple definition of knowledge. Knowledge is just perception of the agreement or disagreement of our ideas. We know the truth of a proposition when we become aware of the relation between the ideas it conjoins. This can occur in any of three distinct ways, each with its characteristic degree of certainty.

 

Intuitive knowledge involves direct and immediate recognition of the agreement or disagreement of two ideas. It yields perfect certainty, but is only rarely available to us. I know intuitively that three is not the same as seven.

 

In Demonstrative knowledge we perceive the agreement or disagreement only indirectly, by means of a series of intermediate ideas. Since demonstration is a chain of reasoning, its certainty is no greater than its weakest link; only if each step is itself intuitively known will the demonstration as a whole be certain. If I know that A is greater than B and that B is greater than C, then I know demonstratively that A is greater than C. Although intuition and demonstration alone satisfy the definition of knowledge, Locke held that the belief that our sensory ideas are caused by existing things deserves the name of sensitive knowledge.

 

Types of Knowledge

Locke distinguished four sorts of agreement or disagreement between ideas, perception of which gives us four distinct types of knowledge: 

 

Since knowledge of Identity and Diversity requires only a direct comparison of the ideas involved, it is intuitive whenever the ideas being compared are clear.

 

Knowledge of Coexistence would provide detailed information about features of the natural world that occur together in our experience, but this scientific knowledge is restricted by our ignorance of the real essences of substances; the best we can do is to rely upon careful observations of the coincidental appearance of their secondary qualities and powers.

 

The degree of certainty in our knowledge of Real Existence depends wholly upon the content of our ideas in each case. Locke agreed with Descartes that we have intuitive knowledge of our own existence, and he supposed it possible to achieve demonstrative knowledge of god as the thinking creator of everything. But we have only sensitive knowledge of the existence of other things presently before our senses.

 

 

The Extent of Knowledge

The result of all of this is that our knowledge is severely limited in its extent. On Locke's definition, we can achieve genuine knowledge only when we have clear ideas and can trace the connection between them enough to perceive their agreement or disagreement. That doesn't happen very often, especially where substances are at issue. The truths of mathematics are demonstrable precisely because they are abstract: since my ideas of lines, angles, and triangles are formed without any necessary reference to existing things, I can prove that the interior angles of any triangle add up to a straight line.

But any effort to achieve genuine knowledge of the natural world must founder on our ignorance of substances. We have "sensitive knowledge" of the existence of something that causes our present sensory ideas. But we do not have adequate ideas of the real essence of any substance, and even if we did, we would be unable to discover any demonstrative link between that real essence and the ideas it produces in us. The most careful observation can establish at best only the secondary qualities and powers that appear to coexist in our experience often enough to warrant our use of them as the nominal essence of a kind of substance.

 

 

 

Source: http://www.philosophypages.com/hy/4m.htm