Philosophy of John Locke


WHAT perception is everyone will know better by reflecting on what he does himself when he sees, hears, feels, tastes, smells or thinks, than by any discourse of mine.

We ought further to consider concerning perception, that the ideas we receive by sensation are often in grown people altered by the judgement without our taking any notice of it.

When we set before our eyes a round globe of any uniform colour--e.g. gold, alabaster or jet--the idea thereby imprinted in our mind is of a flat circle variously shadowed with several degrees of light and brightness coming to our eyes.

But we, having by use been accustomed to perceive what kind of appearances convex bodies are wont to make in us, what alterations are made in the reflections of light by the difference of the sensible figures of bodies, the judgement presently, by an habitual custom, alters the appearances into their causes; so that from that which is truly a variety of shadow or colour collecting the figure, it makes it pass for a mark of figure, and frames to itself the perception of a convex figure and a uniform colour, when the idea we receive from thence is only a plane variously coloured, as is evident in painting.

Perception, then, is the first operation of our intellectual faculties, and the inlet of all knowledge into our minds.

The next faculty of the mind whereby it makes a further progress towards knowledge is that which I call retention, or the keeping of those simple ideas which from sensation or reflection it hath received. This is done, first, by keeping the idea which is brought into it for some time actually in view, which is called contemplation. The other way of retention is the power to revive again in our minds those ideas which after imprinting have disappeared, or have been, as it were, laid aside out of sight; and thus we do when we conceive heat or light, yellow or sweet, the object being removed. This is memory,' the store-house of our ideas.

ANOTHER faculty we may take notice of in our minds is that of discerning and distinguishing between the several ideas it has. It is not enough to have a confused perception of something in general. Unless the mind had a distinct perception of different objects and their qualities, it would be capable of very little knowledge, even though the bodies that affect us were as busy about us as they are now, and though the mind were continually employed in thinking.

On this faculty of distinguishing one thing from another depend the evidence and certainly of several even very general propositions which have passed for innate truths, because men, overlooking the true cause why those propositions find universal assent, impute it wholly to native uniform impressions; whereas it, in truth, depends upon this clear discerning faculty of the mind, whereby it perceives two ideas to be the same or to be different.

The comparing of ideas one with another is the operation of the mind upon which depends all that large tribe of ideas comprehended under relations. The next operation is composition, whereby the mind puts together several simple ideas and combines them into complex ones.

The use of words being to stand as outward marks of our internal ideas, and those ideas being taken from particular things, if every particular idea that we take in should have a distinct name, names must be endless. To prevent this, the mind makes the particular ideas received from particular objects to become general, which is done by considering them as they are in the mind, and such appearnces separate from all other existences and from the circumstances of real existence, as time, place, or any other concomitant ideas.

This is called abstraction, whereby ideas taken from particular being become general representatives of all of the same kind. Thus, the same colour being observed to-day in chalk or snow which the mind yesterday received from milk, it considers that that appearance alone makes it a representative of all of that kind; and having given it the name 'whiteness,' it by that sound signifies the same quality wheresover imagined or met with; and thus universals, whether ideas or terms, are made.

As the mind is wholly passive in the reception of all its simple ideas, so it exerts several acts of its own, whereby, out of its simple ideas, as the materials and foundations of the rest the others are framed. And I believe we shall find, if we observe the originals of our notions, that even the most abstruse ideas, how remote soever they may seem from sense, or from any operation of our minds, are yet only such as the understanding frames to itself, by repeating and joining together ideas that it had either from objects of sense or from its own operations about them; so that even those large and abstract ideas are derived from sensation or reflection, being no other than what the mind, by the ordinary use of its own faculties employed about ideas received from objects of sense, or from the operations its observes in itself about them, may and does attain. This may be shown in our ideas of space, time and infinity, and some others that seem the most remote from these originals.

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