The militancy of Mohammedanism will probably have little effect on the future of the world, because Mohammedan countries are at present poorly organized for extensive modern war. The Church of England is more concerned with the social and international implications of religion than any other, and the above remarks have little relevance to it. If, therefore, the cataclysm above contemplated is to be averted the first necessity would seem to be a revision of the standards of existing religions, in consideration of the unification of the human race, so as to accord with a formula of something of this sort: That is good and morally right which will promote the general happiness and goodwill of humanity, and the harmony of the world. It is clear that action leading to the limitation of over-multiplication would in this sense be good and in accordance with religion. * * * * * The second obstacle to the realization of a control of population is the standard by which the merit of a nation is now generally appraised, and to which most nations aspire. This merit is largely estimated in terms of power of offence and defence. This is a bad criterion and should be altered for a better one which will now be considered. Earlier in the book reference was made to a biological argument against contraception, consideration of which was deferred. This argument holds that in so far as reproduction is a primary biological function, a thwarting of that function is not only unnatural but anti-biological. This view has a certain plausibility but does not stand close scrutiny. The criterion of biological value or fitness is essentially racial, not individual. That is biologically good which will improve or benefit the race, that is bad which will harm or weaken it. Under stable conditions of racial equilibrium there is a reasonable expectation that instincts and structures which have had survival value in the past will continue to have such value in the future. But during moments of crisis, at those turning points in the history of living things when new forms appear, such a presumption is quite unjustified. Thus if we picture to ourselves, allegorically, an event which probably took many thousands of years to accomplish, we might imagine the comments of a conservative piscine critic upon the emergence of the first Dipnoid from some muddy river on to land.