e operation of no causes
but such as could be proved to be actually at work. We wanted, not to
pin our faith to that or any other speculation, but to get hold of
clear and definite conceptions which could be brought face to face with
facts and have their validity tested. The 'Origin' provided us with
the working hypothesis we sought. Moreover, it did the immense service
of freeing us for ever from the dilemma--refuse to accept the creation
hypothesis, and what have you to propose that can be accepted by any
cautious reasoner? In 1857, I had no answer ready, and I do not think
that any one else had. A year later, we reproached ourselves with
dullness for being perplexed by such an inquiry. My reflection, when I
first made myself master of the central idea of the 'Origin,' was, "How
extremely stupid not to have thought of that!" I suppose that
Columbus' companions said much the same when he made the egg stand on
end. The facts of variability, of the struggle for existence, of
adaptation to conditions, were notorious enough; but none of us had
suspected that the road to the heart of the species problem lay through
them, until Darwin and Wallace dispelled the darkness, and the
beacon-fire of the 'Origin' guided the benighted.

Whether the particular shape which the doctrine of evolution, as
applied to the organic world, took in Darwin's hands, would prove to be
final or not, was, to me, a matter of indifference. In my earliest
criticisms of the 'Origin' I ventured to point out that its logical
foundation was insecure so long as experiments in selective breeding
had not produced varieties which were more or less infertile; and that
insecurity remains up to the present time. But, with any and every
critical doubt which my sceptical ingenuity could suggest, the
Darwinian hypothesis remained incomparably more probable than the
creation hypothesis. And if we had none of us been able to discern the
paramount significance of some of the most patent and notorious of
natural facts, until they were, so to speak, thrust under our noses,
what force remained in the dilemma--creation or nothing? It was
obvious that, hereafter, the probability would be immensely greater,
that the links of natural causation were hidden from our purblind eyes,
than that natural causation should be incompetent to produce all the
phenomena of nature. The only rational course for those who had no
other object than the attainment of truth, was to ac