We do not, indeed, assert that this maxim, even when taken in its utmost latitude, contains anything which is absolutely false; but we hope to show that, in its application to the science of man, and as a fundamental rule of psychology, it falls very far short of the whole truth, and is of a very misleading tendency. If it has acted like fanners upon the physical sciences, it has certainly fallen like an extinguisher upon philosophy.
The method laid down in this canon as the only true foundation of science, is the method of observation. The question then comes to be: Can this method be properly applied to the phenomena of man, in exactly the same sense as it is applied to the phenomena of nature? The disciples of Lord Bacon tell us that it can, and must, if we would construct a true science of ourselves; but, in opposition to their opinion, we undertake to show that, in the case of man, circumstances are evolved, which render his observation of his own phenomena of a totally different character from his observation of the phenomena of nature. Let us, then, illustrate the method of observation, first, in its application to nature; and, secondly, in its application to man.
We will call nature and her phenomena B, and we will call the observer A. Now, it is first to be remarked, that in A there is developed the fact of A's observation of B: but the proper and sole business of A being to observe the phenomena of B, and A's observation of the phenomena of B not being a
