, because the earth would have then been too hot to
allow of life, my reply is: "That is not my affair; settle that with
the geologist, and when you have come to an agreement among yourselves
I will adopt your conclusion." We take our time from the geologists and
physicists; and it is monstrous that, having taken our time from the
physical philosopher's clock, the physical philosopher should turn round
upon us, and say we are too fast or too slow. What we desire to know is,
is it a fact that evolution took place? As to the amount of time which
evolution may have occupied, we are in the hands of the physicist and
the astronomer, whose business it is to deal with those questions.

I have now, ladies and gentlemen, arrived at the conclusion of the task
which I set before myself when I undertook to deliver these lectures.
My purpose has been, not to enable those among you who have paid no
attention to these subjects before, to leave this room in a condition
to decide upon the validity or the invalidity of the hypothesis of
evolution; but I have desired to put before you the principles upon
which all hypotheses respecting the history of Nature must be judged;
and furthermore, to make apparent the nature of the evidence and the
amount of cogency which is to be expected and may be obtained from it.
To this end, I have not hesitated to regard you as genuine students and
persons desirous of knowing the truth. I have not shrunk from taking
you through long discussions, that I fear may have sometimes tried
your patience; and I have inflicted upon you details which were
indispensable, but which may well have been wearisome. But I shall
rejoice--I shall consider that I have done you the greatest service
which it was in my power to do--if I have thus convinced you that the
great question which we have been discussing is not one to be dealt with
by rhetorical flourishes, or by loose and superficial talk; but that it
requires the keen attention of the trained intellect and the patience of
the accurate observer.

When I commenced this series of lectures, I did not think it necessary
to preface them with a prologue, such as might be expected from a
stranger and a foreigner; for during my brief stay in your country, I
have found it very hard to believe that a stranger could be possessed
of so many friends, and almost harder that a foreigner could express
himself in your language in such a way as to be, to all appearance, so
readily intel