the psychologist as perfect equality; this would be to confuse measurement with mere perception. Similarity of composite wholes or composite similarity is dealt with under its different forms; then similarity of simple contents or elements. Wherever a sum of sensuous contents is apprehended as a series, as in the case of tones, perceptions of simple similarities are involved.
In a final section of this First Part, the author considers two classes of judgment of peculiar interest in relation to tone-psychology, namely, comparisons of distance, and judgments which presuppose a standpoint. The idea of distance is based on the fact that similarities present themselves in a graduated series. By a distance we mean a certain degree of dissimilarity. The relation may hold between intensities or qualities of sensations or between space and time points. It follows that every judgment respecting distance is at the same time a comparison of distances. We are able with a certain degree of credibility to judge not only that one distance is greater than another but that two distances are equal, e.g., the distances of the compass-points by the aid of the tactual sense in certain experiments of Fechner. A curious point arising here is, whether it is necessary in judging of a distance to represent in imagination the intermediate sensations, in other words the transition from one extreme to another. The author argues that this is not absolutely necessary to a judgment respecting distance. In the case of smell and taste, for example, we may be in a position to say that one pair of sensations are more like one another than another without being able to fill up imaginatively a series of intermediate steps. The author then considers the conditions most favourable to distance-comparison, e.g., absolute magnitude of the distances compared, the presence of a common term in the two pairs compared, &c. The idea of a standpoint is illustrated in judgments respecting time and space, with a hint that judgments about tones will supply a further illustration.
I have purposely given the main outline of Dr. Stumpf's theory respecting sense-judgments before attempting any critical estimate of its value. A word or two may be premised respecting his plan and arrangement. It seems to me that the author in this introduction has given us something more than an introduction and something less than an adequate self-contained discussion of principles. Subjects are opened up and dealt with in a fragmentary way. This is emphatically true, for example, of the subject of attention and its relation to sensation and to judgment. In some cases, again, we have to look for the author's general theory in the second part, that is to say in connexion with the particular facts of tone-judgment. This remark applies for instance to the discussion of so important a point as the threshold or liminal intensity of sensation, a clear conception respecting which, one would say, is essential to any such doctrine of sense-judgment as is here unfolded. So much is this commingling of the general
