Page:Philosophical Review Volume 12.djvu/584

568 think away all space-filling bodies but not space itself, only confirms the result of a scientific analysis of vision. Depth, however, presupposes actual or remembered movement. Now the obviously extensive character of visual perceptions, together with the no less obvious impossibility of perceiving distance by sight alone, refutes the deduction of all the elements in the concept of space from one and the same source. The representation of the extended world is, rather, the result of a psychic synthesis of three distinct spheres of our sensibility, which in their immediate perceptions contain the elements of the following fundamental concepts: (1) Mass, the hypothesis of tactile sensations of resistance or pressure; (2) Force, the hypothesis of muscular sensations, and the subjective aspect of movement; (3) Form, determined qualitatively by color, as a product of vision. The first two senses serve as the basis of our concepts of the solid and the void. The third facilitates the synthesis of the two preceding, because it gives rise to the idea of form, which combines with that of the void, and also the idea of color, which combines with that of a solid. It is vision which transforms the vague notions of solid and void into ideas of geometrical space and of the bodies which fill it. These ideas, which seem to be elementary data of consciousness, are in reality complex products of discursive thought. The analysis just given makes it possible to discover also the psychic sources of four very general postulates of science: (1) the unity of physical forces, (2) the unity of matter, (3) the principle of equality of action and reaction, and (4) the impenetrability of matter. The part played by will in the psychogenesis of extension is of prime importance. The feeling of effort in willing is the basis of the idea of force. This feeling, together with tactile and muscular impressions of resistance, is a constituent part of all movement cousciousnessconsciousness [sic], whether the movement be impeded or free. In the former case, the idea of inertia, in the latter case, that of successful force is the result. But in both there is a clear consciousness of will power. This will or force being the cause of movement, of which space is the indispensable condition and distance the measure, it follows that personal activity is as important as perceptivity in tridimensional space constructions. This dynamic explanation is an essentially modern one.

The weakness of utilitarianism consists in the fact that in the category of moral actions are placed not only those which alleviate pain, but also those which produce positive pleasure. Now the superinduction of pleasure is seen not to be attended with the same kind of feeling on the part of the moral agent as is the alleviation of pain. It is universally recognized that right actions are acts of abstention from the infliction or augmentation of