baize cover which adorns the table in the boardroom.
Another definition of psychology, which is at once a definition by content and a definition by method, has often been employed by philosophers and physiologists. It consists in supposing that there really exist two ways of arriving at the cognition of objects: the within and the without. These two ways are as opposed to each other as the right and wrong side of a stuff. It is in this sense that psychology is the science of the within and looks at the wrong side of the stuff, while the natural sciences look at the right side. And it is so true, they add, that the same phenomenon appears under two radically different forms according as we look at it from the one or the other point of view. Thus, it is pointed out to us, every one of our thoughts is in correlation with a particular state of our cerebral matter; our thought is the subjective and mental face; the corresponding cerebral process is the objective and material face.
Then the difference between representation, which is a purely psychological phenomenon, and a cerebral state which is a material one, and reducible to movement, is insisted upon; and it is declared that these two orders of phenomena are separated by irreducible differences.
Lastly, to take account of the meaning of these