ON EVOLUTION. 281 
doctrines and their expository applications admit of further 
simplification; and there is thus a possibility of making a 
nearer approach to some ultimate principle, which, if dis- 
covered, would account for all things. A new step thither- 
ward may seem to have been lately taken in the theory which 
has necessitated the coining of the word Protyle,* and which, 
perhaps, in some modified form, may be eventually accepted 
as a luminous simplification of the first principles of the 
science of chemistry, and as still further correlating its pheno- 
mena with facts which astronomical observation has brought 
to hght. But in the endeavour to penetrate the mystery of 
an ever-receding past, the increasing risk of mistaking base- 
less speculation for scientific progress renders continually 
more and more needful a clue which the explorer may dis- 
cover if he looks within, and which, therefore, is inevitably 
overlooked by those who, in seeking guidance, confine their 
attention to such outward signs and tokens as seem to point 
out the way. 
9. What I take to be the clue is to be found, not in the 
phenomena that await interpretation, but in the interpreter 
himself, in the resources of that voliticnal power which he 
_ possesses in association with sensibility and reason. For if 
the fundamental principle of evolution be sought, what is 
there in nature to suggest a conception of it so worthy of a 
rational being as that of which we seem to have an inkling 
if we reflect upon that evolution from within ourselves which 
takes place in so far as the outward world reveals us, and our 
own minds account for any phenomena which would be 
wanting but for them? In reference to this question, the 
products of human thought and industry have an unmis- 
takable significance: in the conversion of masses of earthy 
material and of vegetable fibre into elaborate structures 
adapted to the manifold needs of the highest order of 
organic life there is a notable transition from imperfect 
homogeneity to a relative heterogeneity. The cropping-up 
of houses, and villages, and towns, and the developnient of 
those countless tangible evidences of advancing civilisation 
with which they become enriched and adorned, constitute a 
growth, running, in a measure, parallel to that which clothes 
the earth with verdure and breaks out into flowers and 
fruits, and, it may also be affirmed, crowning, so far as this 
planet is concerned, the ascending grades of cosmical 
evolution. 
* “ Address to the Chemical Section of the British Association ” (Bir- 
mingham, 1886,) by William Crookes, p. 11. i 
