John Locke (1632-1704) was the first of the classical British empiricists. (Empiricists believed that all knowledge derives from experience. These philosophers were hostile to rationalistic metaphysics, particularly to its unbridled use of speculation, its grandiose claims, and its epistemology grounded in innate ideas) If Locke could account of all human knowledge without making reference to innate ideas, then his theory would be simpler, hence better, than that of Descartes. He wrote, “Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas: How comes it to be furnished? To his I answer, in one word, from EXPERIENCE.” (Donald Palmer, p.165)
So the mind at birth is a tabula rasa, a blank slate, and is informed only by “experience,” that is, by sense experience and acts of reflection. Locke built from this an epistemology beginning with a pair of distinctions: one between SIMPLE and COMPLEX ideas and another between PRIMARY and SECONDARY qualities. Simple ideas originate in any one sense (though some of them, like “motion,” can derive either from the sense of sight or the sense of touch). These ideas are simple in the sense that they cannot be further broken down into yet simpler entities. (If a person does not understand the idea of “yellow,” you can’t explain it to him. All you can do is point to a sample and say, yellow.) These simple ideas are Locke’s primary data, his psychological atoms. All knowledge is in one way or another built up out of them.
Complex ideas are, for example, combinations of simple ideas. These result in our knowledge of particular things as an apple-derived from the simple ideas “red-spherical-sweet. Locke’s distinction between primary and secondary qualities are primary qualities are characteristics of external objects, which could be size, shape, and location are examples of primary qualities. Secondary qualities are characteristic that are often attribute to external objects, which exist only in the mind, yet are caused by real features of external objects. Secondary qualities are colors, sounds, and tastes.) This view of the mind has come to be known as REPRESENTATIVE REALISM. This mean the mind represents the external world but it does not duplicate it. The mind is something like a photograph in that there are feature of a photo that very accurately represent the world, such as a good picture of three people and that each of them has two eyes, one nose, and one mouth, and there are features of the photograph that belong exclusively to the photo (its glossiness, its two-dimensionality, the white border around its content). A real quality must be a quality of a real thing and real things are substances. Once again, given anything in the world, it is either a substance or a characteristic of a substance.)
So, having claimed that he could account for all knowledge purely in terms of “experience” and having arrived at the concept that had dominated philosophy for the...