CAUSATION AND SIMPLE ENUMERATION 55 



The deduced consequences are that developing individuals 

 probably present traces of ancestral forms. The appeal to reality 

 is the search for such traces. A successful appeal ends in the 

 discovery of them and the proof of the induction. It is agreed on 

 all hands that they do actually occur. 



85. Hitherto, biologists have always founded the notion that 

 development is a recapitulation of evolution on the evidence 

 supplied by embryos. Adopting the method of ' induction from 

 simple enumeration,' they have concluded that the developing 

 young of living beings often resemble organisms lower in the 

 scale of life than the adult type, and thence have deduced the 

 further conclusion that the resemblance is due to a descent from 

 lower forms. That which, rightly used, should have furnished 

 tests, has been made the material on which was built the hypothesis 

 which has remained, therefore, a much controverted working 

 hypothesis. I have endeavoured to establish it as a theory, an 

 invariable law, founded on facts of causation and tested by an 

 appeal to reality. " It cannot be too often repeated, that we ought 

 never to depend on frequency of occurrance, wherever it is 

 possible to have recourse to facts of causation." x " The notion of 

 cause " is " the root of the whole theory of Induction." 2 The facts, 

 all of which are patent, and the reasoning, some of which is 

 deductive, are before the reader. If now, bearing in mind the 

 undisputed truth that offspring recapitulate (with variations) 

 parental development, he is able to conceive individual develop- 

 ment, as anything other than a recapitulation, however altered, of 

 the life-history of the race, he is capable of an intellectual feat 

 which is quite certainly beyond my powers. 



is seen to be obviously inductive. To reach the notion that development is a 

 recapitulation of evolution we merely sum up the persistent variations of the 

 successive generations. 



1 Fowler, Inductive Logic, pp. 270-1. 



2 J. S. Mill, Logic, III. v. 2. If the reader disagrees with the notion that we 

 create better science when we link together our material by facts of causation 

 than when we simply enumerate likenesses and differences, it would be well if 

 he now broke the continuity of this work and, before proceeding further, read 

 chapters xviii. and xxv. Meanwhile, I should be glad if he took this problem 

 of recapitulation as a test case and asked himself which is the better science, 

 the disputable and often disputed guess that is founded on a simple enumeration 

 of the likenesses between embryos and lower forms of life, or the indisputable 

 truth that is demonstrated when, starting with the familiar generalisation that 

 offspring recapitulate the parental development, we establish a chain of causation, 

 and so reach the necessary conclusion that the development of the individual is 

 a brief and inaccurate r<?sum<? of the evolution of the race ? 



