Theories of Life, Mechanical and Vitalistic 327 



material, is necessary to the maintenance even of the 

 genetic point of view as developed in the preceding 

 section. The new genetic mode is the outcome of the 

 old. Each has its twofold character ; its present organi- 

 zation and its future development. The formulations of 

 quantitative science are formulations of the organization 

 given tJie mode. The mode is the statement of new 

 form liable to organization. Each, as in Aristotle's 

 theory, is one aspect of the full truth. This is true also 

 from the point of view of the rise in the mind of the 

 distinction upon which analytic science is distinguished 

 from genetic - - that between the retrospective and the 

 prospective points of view. The very basis of the pro- 

 spective attitude is found in the formulations which are 

 retrospective. All the accommodations by which selec- 

 tive thinking proceeds are projected from the platform 

 of old habitual actions. It is as impossible to construe 

 the one without the other as to construe the other with- 

 out the one. To think is at once to recognize both the 

 analytic and the genetic points of view. 



10. Theories of Life, Mechanical and Vitalistic 



No better illustrations could be wanted of the need of 

 somehow holding together the two points of view on this 

 general question of life than the current discussions of 

 certain critical biological phenomena, such as those of 

 regeneration. The recent book by Morgan a not only lays 

 before us the data of research, but brings to an issue the 

 rival theories. We find the advocates of the chemico- 

 mechanical theory claiming that the data must be con- 



1 Regeneration, by T. H. Morgan, 1901. 



