162 A. BAIN :

one now present restores another not present, yet related according to one or other of the supposed relationships. Thus a word recalls the thing named, by a law of associa- tion founded on the frequent concurrence or proximity of the two in the consciousness. The classifications of these supposed bonds of relationship among ideas are various, and need not be repeated further than to say that two relationships have survived in nearly every classification : I mean Association by Contiguity, and the law of Similars or Similarity. These have a com- manding importance in all the schools of Associationists. Contrast is also admitted as a reproductive force, but, however viewed, is unable to take the same rank as these others. I shall advert to it presently. After a survey of the leading controversies that have clustered round these laws, I mean to devote a considerable space to the problem now uppermost among psychologists, as connected with the terms Attention and Apperception ; taking for the text "Wundt's recent handling in his work on Logic. The settlement of this problem unavoidably re-acts upon all the other controversies. I. The Terminology of Association. This subject is included in Hamilton's elaborate Note, in his Reid, on the history of ' Association '. His objections to the main word itself are (1) that it implies Co-existence, or a connexion between co-existences already known, and (2) that it supposes a bilateral and equal correlation. Also the words, Chain, Concatenation, Series, Train, Movement, are each more or less unsuitable as the leading term for the various operations to be comprised under it. On the whole, Hamilton thinks that "as among the earliest, so perhaps the lest terms for the process of reproduction are to be found in Suggest, Suggestion, Suggestive, Co-suggestive, with their conjugates". The metaphor originally perceptible in these words has now disappeared. Undoubtedly any appropriateness in the term Association is confined to the law of Contiguity, under which the com- panionship of the related ideas is at its maximum of fulness ; seeing that the occasion of their coming together by a process of resuscitation is their being more or less frequently together previously. In Similarity, the resuscitation is not preceded by any previous companionship : the two members that have come together, as a consequence of their resemblance, may have been at the greatest distance from each other in our former experience. Hence, for Similarity,