III. DIVISIONS OF PHILOSOPHY: SPECULATIVE AND PRACTICAL PHILOSOPHY.—The general problem of classifying all the sciences built up by human thought is a logical problem of no little complexity when one tries to work it out in detail. We refer to this general problem only to mention a widely accepted principle on which it is usually approached, and because the division of philosophy itself is a section of the general problem. The principle in question is that sciences may be distinguished indeed by partial or total _diversity of subject-matter_, but that such diversity is not essential, that _diversity of standpoint_ is necessary and sufficient to constitute distinct sciences even when these deal with one and the same subject-matter. Now applying this principle to philosophy we see firstly that it has the same subject-matter as all the special sciences taken collectively, but that it is distinct from all of them inasmuch as it studies their data not from the standpoint of the proximate causes, but from the higher standpoint of the ultimate causes of these data. And we see secondly that philosophy, having this one higher standpoint throughout all its departments, is _one_ science; that its divisions are only material divisions; that there is not a plurality of philosophies as there is a plurality of sciences, though there is a plurality of departments in philosophy.(9) Let us now see what these departments are. If we ask why people seek knowledge at all, in any department, we shall detect two main impelling motives. The first of these is simply the desire to know: _trahimur omnes cupiditate sciendi_. The natural feeling of wonder, astonishment, “_admiratio_,” which accompanies our perception of things and events, prompts us to seek their causes, to discover the reasons which will make them _intelligible_ to us and enable us to _understand_ them. But while the possession of knowledge for its own sake is thus a motive of research it is not the only motive. We seek knowledge _in order to use it_ for the guidance of our conduct in life, for the orientation of our activities, for the improvement of our condition; knowing that knowledge is power, we seek it in order to make it minister to our needs. Now in the degree in which it fulfils such ulterior purposes, or is sought for these purposes, knowledge may be described as _practical_; in the degree in which it serves no ulterior end, or is sought for no ulterior end, other than that of perfecting our minds, it may be described as _speculative_. Of course this latter purpose is in itself a highly practical purpose; nor indeed is there any knowledge, however speculative, but has, or at least is capable of having, some influence or bearing on the actual tenor and conduct of our lives; and in this sense all knowledge is practical. Still we can distinguish broadly between knowledge which has no direct, immediate bearing on our acts, and knowledge that has.(10) Hence the possibility of distinguishing between