I am much engaged, an old man and out of health, and I cannot spare time to answer your questions fully,—nor indeed can they be answered. Science has nothing to do with Christ, except in so far as the habit of scientific research makes a man cautious in admitting evidence. For myself, I do not believe that there ever has been any Revelation. As for a future life every man must judge for himself between conflicting vague probabilities. Wishing you happiness, I remain, &c.
Charles Darwin (Letter to von Müller, June 5, 1879).
This letter is reproduced in the Life and Letters, but evidently Francis Darwin did not know that the “German youth” to whom he says it was written was Baron Ferdinand von Müller, K.C.M.G. (1825-1896), then fifty-three years of age! Von Müller was director of the Melbourne Botanical Gardens from 1857 to 1873, and died in Melbourne in 1896. He did important work in Australian botany.
As regards Darwin’s letter, it seems to me that a sufficient reason why a great and lovable man, who was at first a convinced believer in the immortality of the soul, became an agnostic is given in the next quotation. The higher aesthetic part of his brain had become atrophied.
Darwin himself thought that he had not given sufficient consideration to religious questions and was exceedingly anxious that his own agnostic views should not influence others,
I have said that in one respect my mind has changed during the last twenty or thirty years. Up to the age of thirty, or beyond it, poetry of many kinds, such as the works of Milton, Gray, Byron, Wordsworth, Coleridge, and Shelley, gave me great pleasure, and even as a school-boy I took intense delight in Shakespeare, especially in the historical plays. I have also said that formerly pictures gave me considerable, and music very great delight. But now for many years I cannot endure to read a line of poetry: I have tried lately to read Shakespeare and found it so intolerably dull that it nauseates me. I have also almost lost my taste for pictures or music.... My mind seems to have become a kind of machine for grinding general laws out of large collections of facts, but why this should have caused the atrophy of that (aesthetic) part of the brain alone, on which the higher tastes depend, I cannot conceive.... The loss of these tastes is a loss of happiness, and may possibly be injurious to the intellect, and more probably to the moral character, by enfeebling the emotional part of our nature.
Charles Darwin.
This is from autobiographical notes made by Darwin for his children, and not intended for publication.