a very characteristic doctrine concerning the process of abstraction. In abstraction, namely, one does not really get rid of the diverse features of individual objects and retain only the like elements as giving an idea of a class. The association of the like elements, in a series of objects of experience, with the unlike elements, remains for our consciousness actually the same as at first, except that it is "not so close" as it would be in case one conceived a single individual in isolation. Consciousness is, for our author, always concrete and synthetic. Our relative abstractions we accomplish, in the more complex cases, only by virtue of bringing into consciousness a series of Vorstellungen whose common features are strengthened through Verschmelzung, while the individual features of each Vorstellung are kept in the background by virtue of that very flow of consciousness which helps us to attend to the common features themselves. Abstraction is an affair of attention (p. 48). It does not really sunder, it emphasizes; and for its emphasis it is largely dependent upon the flow of consciousness, which presents the Vorstellungen that are to be the object of the abstracting process.
A passage from this theory of abstraction to the theory of judgment, as indicated above, is contained in our author's doctrine of the significance of language for the thinking process. Abstract ideas are made possible by means of "sprachlicher Ueberlieferung" (p. 49). The imagination is excited to the formation of abstract ideas by the aid and the usage of language (p. 51). In particular the whole activity of judgment depends upon language (p. 20 sqq.). Perception and mere Vorstellen can go on without speech; but judgment, which (p. 1) is the essential characteristic of the thinking process (" unter Denken soll nichts anderes als Urtheilen verstanden werden"), is impossible without some sort of language (pp. 23, 234). Erdmann undertakes more than once, and at considerable length, a psychological proof of this assertion; but admits (p. 224) that a final experimentum crucis is still lacking to demonstrate his position, and no doubt wisely rejects the evidence offered by those cases of aphasia which have been observed and cited with respect to this problem, as insufficient to prove any unmistakable result. Our author is meanwhile far from supposing that the language process is identical with the thinking process, and the observations on pp. 229-231 concerning the relations of the two processes are very instructive, even if one questions Erdmann’s hypotheses concerning the “unconscious” side of the mental life at moments of reading or of hearing a discourse.
Judgment then depends upon language. The data of inner and outer perception, organized through the apperceptive process, give us an enormously complex Vorstellungsleben, where the Verschmelzung of similar elements in series of allied ideas gives rise to multitudinous sorts and
