648 FHAGMKNTS 
it falls in with our belief, \ve should eagerly close with the 
evidence referred to. But there is in the true man of 
science a desire stronger than the wish to have his beliefs 
upheld; namely, the desire to have them true. And those 
to whom I refer as having studied this question, believing 
the evidence offered in favor of ' spontaneous generation ' 
to be vitiated by error, cannot accept it. They know full 
well that the chemist now prepares from inorganic matter 
a vast array of substances, which were some time ago 
regarded as the products solely of vitality. They are 
intimately acquainted with the structural power of 
matter, as evidenced in the phenomena of crystallization. 
They can justify scientifically their belief in its potency, 
under the proper conditions, to produce organisms. But, 
in reply to your question, they will frankly admit their 
inability to point to any satisfactory experimental proof 
that life can be developed, save from demonstrable antece- 
dent life." * 
Comparing the theory oLevolution with other theories, 
I thus express myself : \ The basis of the doctrine of 
evolution consists, not in an experimental demonstration 
for the subject is hardly accessible to this mode of proof 
but in its general harmony with scientific thought. From 
contrast, moreover, it derives enormous relative strength. 
On the one side we have a theory, which converts the 
Power whose garment is seen in the visible universe into 
an Artificer, fashioned after the human model, and acting 
by broken efforts, as man is seen to act. On the other side 
we have the conception that all we see around us and feel 
within us the phenomena of physical nature as well as 
those of the human mind have their unsearchable roots 
in a cosmical life, if I dare apply the term, an infinitesimal 
span of which is offered to the investigation of man." 
Among thinking people, in my opinion, this last concep- 
tion has a higher ethical value than that of a personal 
artificer. Be that as it may, I make here no claim for the 
theory of evolution which can reasonably be refused. 
" Ten years have elapsed," said Dr. Hooker at Norwich 
in 1868, f "since the publication of 'The Origin of 
Species by Natural Selection/ and it is therefore not too 
* Quoted by Clifford, Nineteenth Century, 3, p. 726. 
f President's Address to the British Association. 
