1. There are three general psychological laws of relation. We designate them as the laws of psychical resultants, of psychical relations, and of psychical contrasts.
2. The law of psychical resultants finds its expression in the fact that every psychical compound shows attributes which may indeed be understood from the attributes of its elements after these elements have once been presented, but which are by no means to be looked upon as the mere sum of the attributes of these elements. A compound clang is more in its ideational and affective attributes than merely a sum of single tones. In spacial [sic] and temporal ideas the spacial [sic] and temporal arrangement is conditioned, to be sure, in a perfectly regular way by the cooperation of the elements that make up the idea, but still the arrangement itself can by no means be regarded as a property belonging to the sensational elements themselves. The nativistic theories that assume this implicate themselves in contradictions that cannot be solved; and besides, in so far as they admit subsequent changes in the original space-perceptions and time-perceptions, they are ultimately driven to the assumption of the rise, to some extent at least, of new attributes. Finally, in the apperceptive functions and in the activities of imagination and understanding, this law finds expression in a clearly recognized form. Not only do the elements united by apperceptive synthesis gain, in the aggregate idea that results from their combination, a new significance which they did not have in their isolated state, but what is of still greater importance, the aggregate idea itself is a new psychical content that was made possible, to be sure, by these elements, but was by no means contained in them. This appears most strikingly in the more complex [p. 322] productions of apperceptive synthesis, as, for example, in a work of art or a train of logical thought.
3. The law of psychical resultants which expresses a principle which we may designate, in view of its results, as a principle of creative synthesis. This has long been recognized in the case of higher mental creations, but generally not applied to the other psychical processes.
In fact, through an unjustifiable confusion with the laws of physical causality, it has even been completely reversed. A similar confusion is responsible for the notion that there is a contradiction between the principle of creative synthesis in the mental world and the general laws of the natural world, especially that of the conservation of energy. Such a contradiction is impossible from the outset because the points of view for judgment, and therefore for measurements wherever such are made, are different in the two cases, and must be different, since natural science and psychology deal, not with different contents of experience, but with one and the same content viewed from different sides (§ 1, p. 3). Physical measurements have to do with objective masses, forces, and energies. These are supplementary concepts which we are obliged to use in judging objective experience; and their general laws, derived as they are from experience, must not be contradicted by any single case of experience. Psychical measurements, which are concerned with the comparison of psychical components and their resultants, have to do with subjective values and ends. The subjective value of the whole may increase in comparison with that of its components; its purpose may be different and higher than theirs without any change in the masses, forces, and energies concerned. The muscular movements of an external volitional act, the physical processes that accompany sense-perception, association, and apperception, will follow invariably the principle of the conservation of energy. [p. 323] But the mental values and ends that these energies represent may be very different in quantity even while the quantity of these energies remains the same.
4. The differences pointed out show that physical measurement deals with quantitative values, that is, with quantities that admit of a variation in value only in the one relation of the quantity of the phenomena measured. Psychical measurement on the other hand, deals in the last instance in every case with qualitative values, that is, values that vary in degree only in respect to their qualitative character.
The ability to produce purely quantitative effects, which we designate as physical energy is, accordingly, to be clearly distinguished from the ability to produce qualitative effects, or the ability to produce values, which we designate as psychical energy.