VI
LOCKE’S THEORY OF PERCEPTION
JOHN LOCKE, born three hundred years ago last Au-
gust, was interested primarily in the problem of knowl-
edge. Therefore, I propose to honor him here, not so much
by a biographical account of his intellectual life, as by a clear
statement of certain epistemological propositions he believed
to be important and true. Such commemoration Locke him-
self would have preferred, who often declared while he lived
that the Truth, not John Locke, should be our concern.
The propositions that I shall select for presentation have
to do with perception. Perception, in Locke’s usage, is a term
with a wide application. It is not only “the most general
name for all the operations of the understanding”1 or the
mind, such as sensing, remembering, thinking, imagining,
but also for the immediate objects of these mental opera-
tions, such as a sensed patch of blue, a remembered yester-
day, a thought square root of two, or an imagined unicorn.
Thus, a theory of perception in this wide sense would be an
exhaustive analysis of all the ways of knowing, and this is
precisely what Locke attempts in the Essay. We shall not,
however, take perception in this wide sense as the topic for
our discussion here. Perception, in twentieth-century theory
of knowledge, usually means sense-perception. In Locke’s
own terminology, I am going to present, with an eye for mer-
its and difficulties, his theory of sensation, which claims to
describe some of the physical and mental processes involved
ɪj. Gibson, Locke’s Theory of Knowledge, p. 21. “Perception” is synon-
ymous with “idea.”
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