Philosophy: A Very Short Introduction

with which. (Unsurprisingly, there’s also a lot about cattle and sheep and racehorses; prize dahlias get a mention too.) But that doesn’t take Darwin quite as far as he wants to go, because it is perfectly possible to reply that human breeders can only make quite slight changes, so that all the strikingly different breeds of pigeon, though modified by human practice, must in the first place have come each from birds of its own particular species—they are just too different to have descended all of them from one type of bird. Surely?
Now Darwin’s judgement is at its best. He doesn’t try to prove his point, but just shows that anyone opposing it will have a lot more talking to do. If there was an original fantail pigeon, where is it now found in the wild? Well, perhaps it has become extinct, or lives somewhere frightfully remote. And how about the other distinctive breeds that pigeon-fanciers are interested in—where are their wild relatives? And what of the fact that within these breeds one occasionally finds individuals that closely match the complex colouring of a type of pigeon that does exist in the wild nowadays? So is it that all today’s distinctive breeds had ancestors of the same colouring (although they were distinct species), and are now all either extinct in the wild or at least have never been observed? Well, well, how very surprising . . .
So if it is probable that artificial selection can produce such effects in a relatively short time, is there any natural principle of selection that might produce effects of similar magnitude, and perhaps of far greater magnitude, given an enormously longer time to work in? Yes, because the ‘struggle for existence’ (about which Darwin writes a very interesting chapter) eliminates many individuals before they are able to reproduce. A fantail pigeon will probably mate only if it catches the eye of the breeder; a wild pigeon will not mate unless it withstands the struggle for existence long enough to reach maturity. What is being selected for is in the two cases utterly different. In the second case it is the capacity to withstand the local environmental/ecological conditions, and if these should become harsh the selection process will be brutally efficient.
Once thoughts like these have brought us to see that very substantial change is possible, indeed positively likely, and when we recall (what was only just becoming clear to geologists when Darwin was a young man) that these processes may have been going on for an almost unthinkable length of time, certain observations strike one differently, like those Darwin offers in one of the very few sentences in which human beings figure: ‘The framework of bones being the same in the hand of a man, wing of a bat, fin of the porpoise, and leg of the horse—the same number of vertebrae forming the neck of the giraffe and of the elephant . . . at once explain themselves on the theory of descent with slow and slight successive modifications.’
The nineteenth-century enthusiasm for progress, to which the philosophy of Hegel gave such momentum, predisposed many to understand Darwin as part of the same progressivist movement. His younger contemporary Herbert Spencer (1820–1903), a man of a much more metaphysical, even somewhat Hegelian turn of mind, really was part of it. He was the inventor of the overworked phrase ‘the survival of the fittest’, which can easily be understood as implying that those who survive in the struggle for existence are superior to those who do not. He himself seems to have taken it like that, for in the name of progress he opposed anything that would lessen the intensity of the struggle, like social welfare arrangements.
13. Another variation on a theme much favoured by Victorian cartoonists. Darwin’s message wasn’t to be digested quickly.
This kind of thought soon turned into a movement known as Social Darwinism. The name is inappropriate to the point of being slanderous. Darwin never drew such conclusions, nor would he have done, for no such thing follows. In his system the words ‘the fittest’ simply mean: those best fitted to survive and reproduce under the conditions then obtaining. They have nothing to do with moral, or intellectual, or aesthetic superiority; and they mean nothing at all without the rider ‘under the conditions then obtaining’. If those conditions change, yesterday’s ‘fittest’ may be tomorrow’s no-hopers. One of the many problems about making social application of natural selection like Spencer is that changes in human society can so easily produce changes in the conditions under which they themselves arose. Is the internal combustion engine ‘fitter’ than the horse and cart? In a sense, yes, but only so long as it doesn’t run the world out of oil.
That doesn’t mean that Darwin shouldn’t be allowed to change anyone’s attitudes to anything—far from it. Here is an example. The literary critic and popularist Christian theologian C. S. Lewis once (though I’m sure not only once) found himself lamenting our sexual drives. Given the opportunity, he wrote, most of us would eat too much, but not enormously too much; whereas if a young man indulged his sexual appetite every time he felt like it, and each act led to a baby, he would in a very short time populate an entire village. Which shows, Lewis concluded, just how perverted our natural sexuality has become.
But before you castigate yourself a sinner and start bewailing the lost innocence of the human male, reflect on the lesson of Darwin: what we see here is no perversion of nature; it is simply nature herself, who is not concerned to construct the world in accordance with our moral code or anyone else’s. Few factors will, on average, have as big an effect on the numbers of a man’s children as the strength and frequency of his sexual urges; so if this is itself something which many of his children inherit from him, it is clearly a characteristic which natural selection will