Page:Mind (New Series) Volume 8.djvu/495

PHILOSOPHICAL TERMINOLOGY. 481 only in idea and hope ; while in Biology it seems to break down altogether at first sight. The real aim of that claim was to put aside what could only be thought ; clear and distinct thought holds by sensuous perception, while separating from it. It rejects its subjective factors, in order to present in greater purity its objective content the extension of matter. But here there is no room left for anything which can only be thought ; the parts of matter are real, and only change their place, i.e. their relative position, in motion. The possible is an object of thought alone, hence it seemed a matter of course to reject the possible from reality. In fact, to rationalism everything seems a matter of course, completely natural, which it desires, and it appears so also to itself ; hence it rejects and mocks at the scholastic concepts as meaningless. Even the gravitation of the Newtonian physics was censured by the Cartesians as an occult quality, and the concept of chemical affinity was to its originator Boerhaave nothing more than a new expression for that " sympathy " between bodies or elements which is of such ill-fame to all moderns. To these concepts rationalism gives, at any rate provisionally, a mechanical interpretation. On the other hand it throws aside the concept of vital force altogether, together with all the specific forces of the organism derived from it. For a long time during the last generation it seemed trium- phant here ; it was accepted as an axiom that life could and must be explained only from otherwise known physical and chemical "forces". Now the concept of force itself is indeed only an object of thought ; and this is true again of the differently formulated concept of energy which is latterly being substituted for it. But it is easy to satisfy the realistic claim by reducing all forces to the movements of atoms (invisible parts, as Herbert Spencer says), or by maintaining kinetic energy to be the fundamental form as opposed to all other forms, which are provisionally grouped together as " potential " energies. But a very marked reaction against the rationalistic-mechanical tendencies is just appearing. A vitalistic impulse is again disturbing the biologists ; the accepted law of the conservation of energy, in its change of forms, is itself being opposed to the mechanical explanation, which as an " arbitrary hypothesis " is said to be "already given up"; while the search for mechanical equivalents, notwithstanding its famous success with regard to heat, is said to be hopeless with other forms of energy, such as electricity (Ostwald). This renewed opposition to the previous and persisting motive-force of natural scientific reason depends partly upon a just insight, 31