rare; our ancestors probably thought as we think, only a few with real seriousness, and they only between whiles; but a very little thinking gives man an immense superiority over the lower animals! We have now to ask, first, about the _terms_ in which thought goes on; and we shall find that it may go on in imaginal complexes, in words, and in mental attitudes. We then discuss the _pattern_ of thought; and we shall find that thinking is characterised by the ‘division into pairs’ which we mentioned on p. 205. Lastly, we shall take up, separately, some of the special features of this general pattern. § 62. =Imaginal Processes in Thought: The Abstract Idea.=—A great deal of controversy has raged about the abstract or general idea. We can see to-day that the name is, psychologically, a misnomer. Just as no idea is, in its own right, an idea of memory or of imagination, so also no idea is, in its own right, an abstract idea; _an idea becomes, is made into, an_ =abstract idea= _whenever its context and determination carry the meaning of abstractness and generality_. The associationists, however, looked at things differently; they thought that any idea which _means_ ‘abstract’ must also itself _be_ abstract; and so they distinguished a special class of abstract ideas. We obtain such ideas, they said, in this way: we review a large number of particular ideas, and we separate out the elements that are common to all of them; this common remainder is then a general or abstract idea which represents the whole group of particulars. Thus, “by leaving out of the particular colours perceived by sense that which distinguishes them one from another; and retaining that only which is common to all; the mind makes an idea of colour in abstract which is neither red, nor blue, nor white, nor any other determinate colour.”