Page:Popular Science Monthly Volume 68.djvu/230

 226 be combined or physical chemistry interpolated between physics and chemistry. Similarly anthropology might be placed between physiology and psychology while the first four sciences might be combined as mathematics. How this subdivision is to be carried out is purely a practical question which will be answered differently by different ages and concerning which it is useless to quarrel.

I would like, however, to call attention to the three great divisions: Mathematics, energetics and biology (in the broader sense). They represent the three guiding thoughts which up to the present mankind has brought forth for the purpose of mastering scientifically its experiences. Order is the fundamental thought of mathematics, energy the guiding concept from mechanics to chemistry; for the last three sciences it is life. Mathematics, energetics and biology therefore embrace the whole body of the sciences, while logic precedes them all.

Before entering upon a more detailed consideration of these sciences, it is well to anticipate an objection which may be raised on the basis of the following fact. There are in addition to the previously mentioned sciences (as well as the intermediate ones) many others such as geology, history, medicine, philology, which present difficulties if a place is sought for them in our scheme, and which, nevertheless, demand consideration. It is often characteristic of them that they bear relation to several of the sciences which have been enumerated; and still more characteristic of them is it that they do not search for universal relations as do the pure sciences, but rather treat existing complex objects in order to 'explain' or discover their origin, extent, distribution, in a word their time and space relations. To accomplish this object they make use of the relations which the pure sciences have put at their disposal. It is best to designate these sciences as applied sciences. This term is not meant to imply either exclusively or even chiefly technical application. It is merely intended to express the fact that here interrelations of the parts of a ready-made object are rendered intelligible by the application of the general laws which have been discovered by pure science.

In a problem of this nature it is usually necessary to make use of several different pure sciences simultaneously for an explanation, because the abstract method of the pure sciences is not permissible here. To omit certain parts and to limit oneself to certain others is from the very nature of the problem out of the question. Astronomy is an applied science of this sort. It is based immediately upon mechanics; in its instrumental part upon optics; while in its contemporaneous spectroscopic development it borrows much from chemistry. Thus history is applied sociology and psychology; medicine makes use of all preceding sciences up to psychology, etc.

It is important to realize the nature of these applied sciences since