The doctrines of historicism which I have called ‘pro-naturalistic’ have much in common with its anti-naturalistic doctrines. They are, for example, influenced by holistic thinking, and they spring from a misunderstanding of the methods of the natural sciences. Since they represent a misguided effort to copy these methods, they may be described as ‘scientistic’ (in Professor Hayek's sense 1 ). They are just as characteristic of historicism as are its anti-naturalistic doctrines, and perhaps even more important. The belief, more especially, that it is the task of the social 97sciences to lay bare the law of evolution of society in order to foretell its future (a view expounded in sections 14 to 17, above) might be perhaps described as the central historicist doctrine. For it is this view of a society moving through a series of periods that gives rise, on the one hand, to the contrast between a changing social and an unchanging physical world, and thereby to anti-naturalism. On the other hand, it is the same view that gives rise to the pro-naturalistic—and scientistic—belief in so-called ‘natural laws of succession’; a belief which, in the days of Comte and Mill, could claim to be supported by the long-term predictions of astronomy, and more recently, by Darwinism. Indeed, the recent vogue of historicism might be regarded as merely part of the vogue of evolutionism—a philosophy that owes its influence largely to the somewhat sensational clash between a brilliant scientific hypothesis concerning the history of the various species of animals and plants on earth, and an older metaphysical theory which, incidentally, happened to be part of an established religious belief. 2