This puts a new face upon the question of the origin and development of human abstractions and consequent general ideas. It has been commonly supposed that animals had ‘recepts’ or such semi-abstractions as Morgan’s ‘predominants,’ and that by associating with these, arbitrary and permanent signs, such as articulate sounds, one turned them into genuine ideas of qualities. Professor James has made the simple but brilliant criticism that all a recept really means is _a tendency to react in a certain way_. But I have tried to show that the fact that an animal reacts alike to a lot of things gives no reason to believe that it is conscious of their common quality and reacts to that consciousness, because the things it reacts to in the first place are not the hard-and-fast, well-defined ‘things’ of human life. What a ‘recept’ or ‘predominant’ really stands for is no thing which can be transformed into a notion of a quality by being labelled with a name. This easy solution of the problem of abstraction is impossible. A true idea of the problem itself is better than such a solution. My statement of what has been the course of development along this line is derived from observations of animals’ behavior and Professor James’ theory of the nature of and presumable brain processes going with the abstractions and conceptions of human consciousness, but it is justified chiefly by its harmony with the view that conception, the faculty of having general notions, has been naturally selected by reason of its utility. The first thing is for an animal to learn to react alike only to things which resemble each other in the _essential_ qualities. On an artificial, analytic basis, feelings of abstract qualities might grow out of reacting alike to objects similar in such a respect that the reaction would be useless or harmful. But in the actual struggle for existence, starting with the mammalian mind as we have found it, you will tend to get reactions to the _beneficial_ similarities by selection from among these so-called mistakes, _before you get any general faculty of noticing similarities_. In order that this faculty of indifferent reaction to different things shall grow into the useful faculty of indifferent reaction to different things _which have all some quality that makes the reaction a fit one_, there must be a tremendous range of associations. For a lot of the similarities which are non-essential have to be stamped out, not by a power of feeling likeness, but by their failure to lead to pleasure. With such a wide range of associations we may get reactions on the one hand where impulses have been connected with one particular sense-impression because when connected with all others they had failed to give pleasure, and on the other hand, reactions where an impulse has been connected with numerous different impressions possessing one common quality, and disconnected with all impressions, otherwise like these, which fail to have that one quality.