the essential changes, which the resulting idea undergoes, if one of these sensation or affective factors is altered in some marked degree. Just as elements of consciousness are joined together by fusion into compounds, so these compounds themselves undergo manifold changes, out of which new combinations arise. Of great importance among these associations of the second class are those which we shall call assimilations and dissimilations. As ideational combinations they can be easily demonstrated, whereas the corresponding affective associations are joined to them rather as secondary components or form a special class of complex feelings, which are connected with the processes of recollection, recognition, memory, &c, and which we shall treat of in detail later on. Let us first of all glance at some of the most important phenomena in connection with assimilation and dissimilation. To begin with the simplest case, we let one object of sight work in an assimilating manner upon another. We can achieve this most readily if we first of all make the difference between the two objects very small, and if secondly we bring them into a familiar relationship to each other, and so promote the idea of their identity. For example, we draw from one and the same centre sectors of a circle, and make one less than the others only by a few degrees. In spite of this we are inclined to apprehend all the sectors as equal. The larger ones work assimilatively upon the smaller one. To cause the opposite process of dissimilation, we draw one large sector among several smaller sectors. This appears, in contrast to the surrounding smaller sectors, very much enlarged, and we can convince ourselves of this by drawing on another piece of paper a sector of the same size as the one changed by dissimilation. This independent sector will then appear smaller than the one of its own size that is lying among the smaller sectors. This dissimilative change is generally called a contrast. We must not, however, confuse this dissimilative contrast with the contrast of feelings, where it is not a case of the formation of apparent differences in size, but of qualitative contrasts, such as pleasure and displeasure, or the increase of these.