The Role of the Observer

HE distinction between psychology, logic, and [t epistemology is a commonplace. The first treats of experience as an act, experience in its relation to the individual observer. The second concerns itself with the internal marks by which truth may be distinguished from error, and in so far as it deals with experience, has to do with some sort of validity of the experience as evidence of a truth. The third discusses in a general way all the elements-observer, object, immediate presentation-which enter into the experience. There is clearly a rough practical distinction between these three ways of regarding experience. The interests of an investigator of colour vision are certainly different from those of an investigator of mathematical technique, and both are different from those of a speculator in the theory of knowledge. However, the assertion that psychology and logic are two different sciences may mean something much deeper. There are those who make the distinction absolute, and who assert dogmatically that the logical value of a proposition is entirely unconnected with the relation of this proposition to any observer. The Platonist believes in a world of essence, of cleanly defined Ideas and cleanly defined propositions concerning these Ideas, into which we may enter as spectators, but never as participants. They are out of time, and time is irrelevant to them. This is pure dogma, and does not check with what we should naively expect. Of course, our experiences must have some ref-