PHILOSOPHICAL BIOLOGY 465
the one or a very few things which the experimenter must of necessity make the object of each special piece of work.
Although the practical biologist knows that his strivings after expla- nation are utterly futile unless always accompanied by description the spell of subjectivistic metaphysics is still so strong over science that not many biologists have yet grasped the fact that all true explanation is reached through description. Investigators rarely seem to notice that the explanations they propose are usually in reality hypotheses, and that the proof, or the greater or less probability of truth of these explanations (hypotheses) are wholly dependent upon the accuracy and fullness of description to which the organisms are subjected in the aspects of them to which the explanations pertain. Take the classic case of Goethe^s explanation of the fiower as a transformed branch with its leaves. Is it not true that just in so far as this explanation is accepted it is done on the basis of the accepted descriptions of flowers and branches and leaves ? If a true explanation of cancer is ever, reached does any one fail to recognize, when he thinks about the matter, that it must come in the form of well- verified description and classification of the whole complex of organic phenomena implicated in the disease?
A true though incomplete distinction between description in the ordi- nary sense and explanation in the ordinary sense is that the process of describing is very little guided by hypothesis, while explaining is very largely so guided.
Early in the paper, I promised to say something about the baneful effects that have flowed from the neglect by modern biology of the prin- ciples of description and classification. Sine systeme chaos, is the motto standing at the head of an elaborate, recently published work on the arrangement of the animal kingdom. This motto should be adopted, in substance at least, for any and every comprehensive biological treatise, no matter in what field; and I insist that failure to adopt it has thrown the speculative biology of our time into a literal state of chaos.
The revolt against the dry and formal nomenclatorialism into which biology had wandered in the period immediately preceding Darwin, has gone so far as practically to deny that many of the really best estab- lished, most important names in biology have any essential meaning at all. Witness, for example, the effort now taking shape with a few biolo- gists, notably with J. S. Haldane, "to raise the term organism to the level of a categoiy," as Henderson has characterized Haldane's under- taking. As a matter of fact, the effort is to restore, not to originally elevate the term, for a study of the history of biological theory clearly discloses that the term organism was long ago accepted as a category in the very best writings. For example, whenever the cell is interpreted as an " elementary organism/' as it has usually been since Briicke first
VOL. in. — 32.
�� �
