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 unable 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 accept
     ‘Darwinism’ as a working hypothesis, and see what could be made
     of it.  Either it would prove its capacity to elucidate the fact
     of organic life, or it would break down under the strain.  This
     was surely the dictate of common sense, and for once common-sense
     carried the day.  The result has been that complete volte-face
     of the whole scientific world which must seem so surprising to
     the present generation.  I do not mean to say that all the leaders
     of biological science have avowed themselves Darwinians; but I do
     not think that there is a single zooelogist, or botanist, or
     palaeontologist, among the multitude of active workers of this
     generation, who is other than an evolutionist profoundly
     influenced by Darwin’s views.  Whatever may be the ultimate fate
     of the particular theory put forth by Darwin, I venture to affirm
     that, so far as my knowledge goes, all the ingenuity and all the
     learning of hostile critics has not enabled them to adduce a
     solitary fact of which it can be said that it is irreconcilable
     with the Darwinian theory.  In the prodigious variety and
     complexity of organic nature, there are multitudes of phenomena
     which are not deducible from any generalisation we have yet
     reached.  But the same may be said of every other class of natural
     objects.  I believe that astronomers cannot yet get the moon’s
     motions into perfect accordance with the theory of gravitation.”