=The survival of the fittest.=--Now let us look closely at this most famous of all Spencer's phrases, “the survival of the fittest,” and try to understand its full and exact meaning. There is no phrase in any language so frequently misinterpreted. Even a writer who should know better makes this mistake. Mr. H. G. Wells speaks[8] of “that same lack of a fine appreciation of facts that enabled Herbert Spencer to coin those two most unfortunate terms _Evolution_ and the _Survival of the Fittest_. The implication is that the _best_ reproduces and survives. Now really it is the _better_ that survives and not the _best_.” What the correction is supposed to signify I do not know, but the whole passage is nonsense. The implication is neither that the _best_ nor the _better_ survive, but the fittest--or if Mr. Wells prefers, for it matters not one whit--the fitter. This lack of a fine appreciation of words is not, unfortunately, peculiar to Mr. Wells. There is no word in the language that more exactly expresses the fact than the word fittest: as Darwin recognised when he promptly incorporated Spencer's phrase in the second edition of the _Origin of Species_ as the best interpretation of his own phrase “natural selection”![9] Fitness is the capacity to fit: a thing that is fit is a thing that _fits_. A living creature survives in proportion as it fits its environment--the physical environment in the case of vegetables and the lower animals, the physical, social, intellectual and moral environment in the case of man. The kind of glove that most perfectly fits the hand is the fittest glove and will survive in the struggle for existence between gloves. If, instead of a glove, we take a living creature, say a microbe, the kind of microbe that best fits into the environment provided by, say, human blood, is the fittest and will survive and be the cause of our commonest disease. Thus the tubercle bacillus is at once the _fittest_ microbe and, not the best, but the worst. Among ourselves, the newspaper devoted to yesterday's murder is the fittest and survives, ousting the newspaper which reckons with the crucifixion, or the murder of Socrates or Bruno. In a society of blackguardism, the biggest blackguard is the fittest man and will survive: he is also the worst. In another society the best man is the fittest and survives. The capacity to fit into the environment is the capacity that determines survival: it has no moral connotation whatever. If Herbert Spencer had written the survival of the better, as Mr. Wells desires, he would have written palpable nonsense: as it was he used the fittest word--in this case also the best, because the truest. Referring to the queen-bee, who destroys her own daughters, Darwin says, “undoubtedly this is for the good of the community; maternal love or maternal hatred, though the latter fortunately is most rare, is all the same to the inexorable principle of natural selection.”