32 THE THEORY OF [pt. 



level would seem to be, as it were, underneath the metrical abstrac- 

 tions of physics, i.e. outside science altogether, and if this is realised, 

 the vitalist and the mechanist will fuse into one and the same 

 person — a happy consummation. It is curious that at the present 

 time, when physics is so markedly freeing itself from scientific 

 naturalism, biologists are sometimes found to support that untenable 

 world-view, while still farther away from the inorganic world, 

 literary criticism tries to make itself modern by using a psychological 

 jargon, and applying to its problems all the rigour of a materialist 

 metaphysic. 



Neo-mechanism as a Theory for Chemical Embryology 



The principal philosophical obstacles to physico-chemical embryo- 

 logy have now been assessed and nothing remains but to outline its 

 own theoretical basis. Anyone who was dissatisfied twenty years ago 

 with the various forms of neo-vitalism which have already been 

 discussed would have had no alternative but to accept the simple, 

 though rather incredible, scientific naturalism of the preceding 

 century, unless, indeed, he was acquainted with German philosophy, 

 and understood the momentous consequences which flowed from the 

 apparently technical question, "How are a priori synthetic judgments 

 possible?" The varieties of neo-vitalism may perhaps be thought of, 

 in so far as they are not modern forms of difficulties which have 

 for many centuries perplexed philosophers, as a series of reactions 

 against mechanistic biology insufficiently distinguished from scientific 

 naturalism. This confusion is well seen in the earlier phases of the 

 American discussion which led up to the symposium of 191 8. It is 

 often difficult to tell, as in the papers of Nichols; Ritter; More and 

 Fraser Harris, whether the writer is attacking the mechanical theory 

 of the universe regarded as an ultimate metaphysical faith or the 

 mechanical methodology of science. 



Before the eighteenth century, of course, there had always been 

 thinkers who felt the necessity of including both teleology and its 

 antithesis in their systems of thought. This pull in two directions 

 accounts for those very interesting mediaeval theologians, such as 

 Siger of Brabant and John of Jandun, who wished to acknowledge 

 two kinds of truth, theological and philosophical (see Maywald and 

 Gilson). A right balance had to be struck in some way between 

 Democritus and Plotinus, and in the seventeenth century, for in- 



