PHILOSOPHICAL BIOLOGY 461
word man is merely thought of aB applying to the individuals of the human species^ its meaning in extension is before us. When^ on the other hand^ thought goes to the attributes of man^ to what makes him a man^ rather than to individual men^ it is occupied with the meaning in intension of the word.
Now^ as to our point about the second^ the analytic classification of man — ^the analytic meaning of the word man. Let us begin with the reminder that meaning in intension is concerned not with the mere naming of objects^ but with the attributes of the objects named.
Let the reader recall that taxonomic research in both zoology and botany has for years^ so far as it has been based on morphology exclu- sively, taken as one of its guiding principles neglect nothing. This means, stated in the terms of logic, that this aspect of taxonomy has incorporated into its purpose and method, the study of terms in their intension. This is really, I believe, what was in Huxley^s mind, at least in the back-ground of it, when he asserted that the second kind of classification is the '^same thing as the accurate generalization of the facts of form.
A prime object of this paper is to contend that biology has now reached a stage in its progress where we can no longer restrict our dictum " neglect nothing " to morphological attributes, but must extend it to all attributes of organisms whatever — ^morphological, physiological, ecological, chemical and all the rest. And it should be pointed out that the movement of biology in this direction was more or less dis- tinctly seen by at least one biologist nearly a century ago, namely, Q. B. Treviranus. "The doctrine of organization, he said, "is founded upon comparative anatomy, oi the systematic distribution of living bodies, and on organic chemistry."
I believe a comprehensive review of the whole range of biological results won during the last five and twenty years, let us say, will con- vince any one that each of the main provinces of research — comparative physiology, ecology, experimental behavior, genetics and biochemistry, no less than histology, cytology, embryology and regeneration, would furnish differentia for a classification of the organisms used in the re- searches; or at least that they contain differentia corresponding to the systems of classification previously established on the basis of pure morphology.
What does this signify for the attitude of biologists toward their problems, and for methods and enterprises of research ?
It signifies many things, one of which particularly concerns us now, and may be put into the following general proposition: No biological phenomenon is adequately interpreted or dealt with experimentally, until it has been considered with reference to the place which the organ- isms to which it pertains hold in the system of classification. To illus-
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