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 schoolboy 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 nauseated me.I have also almost lost my taste for pictures or music.Music generally sets me thinking too energetically on what I have been at work on, instead of giving me pleasure.I retainsome taste for fine scenery, but it does not cause me the exquisite delight which it formerly did.On the other hand, novels which are works of the imagination, though not of a very high order, have been for years a wonderful relief and pleasure to me, and I often bless all novelists.A surprising number have been read aloud to me, and I like all if moderately good, and if they do not end unhappily-- against which a law ought to be passed.A novel, according to my taste, does not come into the first class unless it contains some person whom one can thoroughly love, and if a pretty woman all the better.
This curious and lamentable loss of the higher aesthetic tastes is all the odder, as books on history, biographies, and travels (independently of any scientific facts which they may contain), and essays on all sorts of subjects interest me as much as ever they did.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 part of the brain alone, on which the higher tastes depend, I cannot conceive.A man with a mind more highly organised or better constituted than mine, would not, I suppose, have thus suffered; and if I had to live my life again, I would have made a rule to read some poetry and listen to some music at least once every week; for perhaps the parts of my brain now atrophied would thus have been kept active through use.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.
My books have sold largely in England, have been translated into many languages, and passed through several editions in foreign countries.I have heard it said that the success of a work abroad is the best test of its enduring value.I doubt whether this is at all trustworthy; but judged by this standard my name ought to last for a few years.Therefore it may be worth while to try to analyse the mental qualities and the conditions on which my success has depended; though I am aware that no man can do this correctly.
I have no great quickness of apprehension or wit which is so remarkable in some clever men, for instance, Huxley.I am therefore apoor critic: a paper or book, when first read, generally excites my admiration, and it is only after considerable reflection that I perceive the weak points.My power to follow a long and purely abstract train of thought is very limited; and therefore I could never have succeeded with metaphysics or mathematics.My memory is extensive, yet hazy: it suffices to make me cautious by vaguely telling me that I have observed or read something opposed to the conclusion which I am drawing, or on the other hand in favour of it; and after a time I can generally recollect where to search for my authority.So poor in one sense is my memory, that I have never been able to remember for more than a few days a single date or a line of poetry.
Some of my critics have said, "Oh, he is a good observer, but he has no power of reasoning!" I do not think that this can be true, for the 'Origin of Species' is one long argument from the beginning to the end, and it has convinced not a few able men.No one could have written it without having some power of reasoning.I have a fair share of invention, and of common sense or judgment, such as every fairly successful lawyer or doctor must have, but not, I believe, in any higher degree.
On the favourable side of the balance, I think that I am superior to the common run of men in noticing things which easily escape attention, and in observing them carefully.My industry has been nearly as great as it could have been in the observation and collection of facts.What is far more important, my love of natural science has been steady and ardent.