of familiar sense-data provokes the terrifying sense of vague presences, effective for good or evil ever our fate. Most living creatures, of daytime habits, are mere nervous in the dark, in the absence of the familiar visual sense-data. But according to Hume, it is the very familiarity of the sense-data which is required for causal inference. Thus the sense of unseen effective presences in the dark is the opposite of what should happen.
4. Primitiveness of Causal Efficacy.
The perception of conformation to realities in the environment is the primitive element in our external experience. We conform to our bodily organs and to the vague world which lies beyond them. Our primitive perception is that of ‘conformation’ vaguely, and of the yet vaguer relata ‘oneself’ and ‘another’ in the undiscriminated background. Of course if relationships are unperceivable, such a doctrine must be ruled out on theoretic grounds. But if we admit such perception, then the perception of conformation has every mark of a primitive element. One part of our experience is handy, and definite in our consciousness; also it is easy to reproduce at will. The other type of experience, however insistent, is vague, haunting, unmanageable. The former type, for all its deco-
