88 



SCIENCE. 



[N. S. Vol. XX. No. 498. 



erty might be called. But such a discovery- 

 would not end the physico-biologieal contro- 

 versy, nor have any serious effect upon it, 

 since we know already that the ' chemical com- 

 pound ' termed protoplasm, however originated, 

 has numerous activities not shared by other 

 compounds, and explainable only by the pred- 

 ication of numerous thus far unexplained 

 properties, such as assimilation, growth, irri- 

 tability, reproduction, etc. 



The biochemist hopes to make protoplasm in 

 a beaker, but in transforming his homogeneous 

 jelly into a ' sprig of moss ' he will need to 

 utilize agencies not only unexplained, but not 

 even analogous to the postulates or properties 

 now ascribed to unorganized matter. These 

 agencies or properties of life are doubtless as 

 ' natural ' as those treated in physics and 

 chemistry, but they are different. To call them 

 ' creative ' or ' directive ' is, perhaps, open to 

 objection, but they are certainly conservative, 

 coordinative and constructive in a manner 

 and degree for which we have no extravital 

 analogy. The directive idea, however, is by 

 no means extinct among biologists. Naegeli's 

 ' Vervolhommungsprincip ' has been succeeded 

 by an equally hypothetical ' mechanism of 

 heredity ' which Professor Weismann and his 

 numerous followers are still seeking in germ- 

 cells. It is possible, however, to frame an evo- 

 lutionary theory without recourse either to 

 ' phyletie vital force ' or to incredibly com- 

 plicated and yet inadequate mechanical de- 

 terminants.* 



It is needless to fear that Lord Kelvin will 

 destroy the fact of organic evolution estab- 

 lished by Darwin, but, on the other hand, no 

 amount of argument can rehabilitate Dar- 

 win's first theory of the developmental process, 

 that the environment causes variations and 

 then selects the desirable changes. This view 

 was abandoned, by Darwin himself, and is now 

 held in its original logical integrity by very 

 few working biologists, the non-inheritance of 

 acquired characters having rendered it un- 

 tenable. T]'T present multiplicity of theories 



* ' A Kinetic Theory of Evolution,' Science, 

 N. S., XIII., 969, June 21, 1901 ; ' Stages of Vital 

 Motion,' The Popular Science Monthly, LXIII., 

 14, May, 1903. 



of development is a sufficient indication that 

 there is, as yet, no generally accepted explana- 

 tion of evolution or of the other characteristic 

 properties of life, and no ' complete mechanical 

 theory of the universe.' Lord Kelvin will per- 

 form an important service for biologists if 

 he encourages them to attempt an adequate 

 formulation of the ascertained facts of their 

 own science instead of thinking it necessary 

 to base their structure on terms and concepts 

 borrowed from widely separate fields of re- 

 search. 



The Vocabulary of Science. — The interest 

 of such a discussion as that precipitated by 

 Lord Kelvin is not confined to the varied 

 opinions advanced; it furnishes also an ex- 

 cellent example of the more general and funda- 

 mental fact that the ' advancement of science ' 

 depends quite as much upon expression as 

 upon investigation. This is true not merely 

 because it is necessary to frame intelligible 

 statements of scientific results which are to be 

 of practical use> but because investigation it- 

 self can not advance far beyond the language 

 in which its results must be interpreted. The 

 rational arrangement or classification of facts 

 is supposed to distinguish the methods and 

 discoveries of science from those of mere acci- 

 dent and empiricism. 



As soon as they leave concrete data and 

 distinctions, scientific men fall to dogmatizing 

 like any other theologians, metaphysicians or 

 philosophers. This is not, however, because of 

 any special inconsistency or weakness, but 

 because all are at the mercy of an inadequate 

 vocabulary and can say only what has been 

 said already, or something sufficiently similar 

 to require a new word only now and then. 

 On the borders of knowledge each word does 

 duty for a great variety of ideas, and the same 

 proposition often conceals essential diversity 

 of thought. The less known about a subject 

 the easier to dogmatize, or to formulate and 

 establish a vocabulary, and an established vo- 

 cabulary is a fact to be reckoned with as much 

 as any other. 



Science and general literature are thus for- 

 ever at war because, while comprehension ad- 

 vances from the concrete and particular to the 

 general, the language in which ideas must be 



