And now I feel that it is due to you to speak as frankly as you have
done to me. An old and worthy friend of mine tried some three or four
years ago to bring us together--because, as he said, you were the only
man who would do me any good. Your letter leads me to think he was
right, though not perhaps in the sense he attached to his own words.

To begin with the great doctrine you discuss. I neither deny nor affirm
the immortality of man. I see no reason for believing in it, but, on the
other hand, I have no means of disproving it.

Pray understand that I have no a priori objections to the doctrine. No
man who has to deal daily and hourly with nature can trouble himself
about a priori difficulties. Give me such evidence as would justify me
in believing anything else, and I will believe that. Why should I not?
It is not half so wonderful as the conservation of force, or the
indestructibility of matter. Whoso clearly appreciates all that is
implied in the falling of a stone can have no difficulty about any
doctrine simply on account of its marvellousness. But the longer I live,
the more obvious it is to me that the most sacred act of a man's life is
to say and to feel, "I believe such and such to be true." All the
greatest rewards and all the heaviest penalties of existence cling about
that act. The universe is one and the same throughout; and if the
condition of my success in unravelling some little difficulty of anatomy
or physiology is that I shall rigorously refuse to put faith in that
which does not rest on sufficient evidence, I cannot believe that the
great mysteries of existence will be laid open to me on other terms. It
is no use to talk to me of analogies and probabilities. I know what I
mean when I say I believe in the law of the inverse squares, and I will
not rest my life and my hopes upon weaker convictions. I dare not if I