The law of resultants finds a supplement and a specific application in the principle of the heterogony of ends in certain very important cases. In the same way we find, as supplementary to the law of relations, "the principle of intensifying contrasts." It includes those relations of psychical elements and compounds which are connected with certain limiting values of the qualitative and quantitative components of a whole. In the region of ideational combinations we have noted such influences of contrast in associative assimilations and dissimilations. We saw there that at a certain limiting value of the difference between two sensations or ideas, e.g. two spatial or temporal distances, two sound or light sensations, the assimilation present at a small difference may turn suddenly into a dissimilation. The impressions no longer assimilate, but become intensified through contrast. In another especially important form we meet the same principle in the feelings, where it stands in connection with the duality of the feelings that is valid for all affective processes and their combinations. In consequence of this each feeling, as we have seen, possesses its contrast-feeling, e.g. pleasure and displeasure, excitation and quiescence, strain and relaxation. Here the principle of relations shows itself in the form of the law of contrast, above all in the fact that the change between contrasting feelings itself intensifies the contrasts. Thus a feeling of pleasure is more intense, and its specific quality is more clearly felt, if it has been preceded by a feeling of displeasure. A similar relation exists between excitation and quiescence, strain and relaxation.