the world as ordinarily conceived by philosophers, not only in being acceptable to common sense, but to science as well. For the scientist dislikes the transcendental egos and shadows of philosophy as much as does the plain man, though for a different reason. They interfere with his business of discovering the relations of resemblance and difference, of coexistence and sequence, that hold between objects. In a world in which there are neither transcendent substances, on the one hand, nor the half real states of those substances, on the other, but only sensible objects and their relations, the scientist is at home.
The utility of Humean realism for purposes of scientific description may be briefly illustrated by showing its bearing upon the psycho-physical problem. (And let us bear in mind that by perception Hume means nothing less than objects of immediate experience, such as stones, mountains, chairs, etc. As we ordinarily use the term, it possesses a subjectivistic connotation which would make it impossible for us to speak of a perception as extended or colored or as existing outside of consciousness, but these predicates can be, and are, applied to the objects which we immediately perceive.) We must think of consciousness neither as a transcendent substance nor as a unique series of qualities, but rather as a peculiar nexus of relations between its objects which, under certain circumstances, supervenes upon the permanent and merely physical relations of space and time. A physical system, without ceasing to be physical, becomes a psychical system whenever its members sustain to one another those relations which make possible an individual consciousness of them.[1] In the world which Hume suggests, the mind-body problem presents itself in a new and less hopeless light, as the problem of
- ↑ In an article on "Time Perception" printed in the American Journal of Psychology for January, 1904, the present writer defined the conditions for the origin and cessation of the experience of a 'specious present' as identical with those for the origin and cessation of consciousness or subjectivity in general. An effort was made to show that consciousness and specious presentness are made possible by that property of a system in virtue of which the form or collective aspect of the system is a more stable and potent factor in its behavior than the individual intensities of its elements. Experience would seem to indicate that a system possessing this peculiar property cannot originate apart from a highly developed protoplasmic matrix or nervous system.
