fact belonging to B, it, of course, does not call for any notice whatsoever from A. It would be altogether irrelevant for A, when observing the phenomena of B, to observe the fact of his own observation of these phenomena. Therefore, in the natural sciences, the fact of A's observation of B is the point looked from, and cannot become the point looked at, without a departure being made from the proper procedure of physics. These sciences, then, are founded entirely on the method of simple observation. Observatio simplex is all that is here practised, and is all that is here necessary; and, whenever it shall have been put forth in its fullest extent, the science of B, or nature, may be considered complete.
Let us now try how the same method of simple or physical observation works in its application to psychology. We will call man and his phenomena A; and, as man is here the observer as well as the observed, we must call the observer A too.
Now, it is obvious that in A (man observed) there are plenty of phenomena present, his sensations, "states of mind," &c., and that A (man observing) may construct a sort of science out of these by simply observing them, just as he constructed the natural sciences by observing the phenomena of B. And this is precisely what our ordinary psychologists have done, adhering to the Baconian canon. But the slightest reflection will show us that such a science of man must necessarily be a false one,
