the eyes of the reader an assortment of psychological phenomena and then saying: “These are the things psychology studies.” One will take readily as samples the ideas, reasonings, emotions, and other manifestations of mental life. If this is only a strictly provisional definition, a simple introduction to the subject, we accept it literally. It may serve to give us a first impression of things, and to refresh the memories of those who, by a rather extraordinary chance, would not doubt that psychology studies our thoughts. But whatever may be the number of these deeply ignorant persons, they constitute, I think, a negligible quantity; and, after these preliminaries, we must come to a real definition and not juggle with the problem, which consists in indicating in what the spiritual is distinguished from the material. Let us leave on one side, therefore, the definitions by enumeration.
Now comes the definition by method. Numbers of authors have supposed that it is by its method that psychology is distinguished from the other sciences.
To the mind is attached the idea of the within, to nature the idea of being without the mind, of constituting a “without” (un dehors). It is a vague idea, but becomes precise in a good many metaphors, and has given rise to several forms of speech. Since the days of Locke, we have
