Hobbes, however, was an individualist as well as Locke, and for Hobbes the individual was the scientific unit from which societies and states were built up—­the starting-point for a scientific treatment of society.  As the French Revolution gave a fresh impulse to idealistic individualism, the Industrial Revolution reanimated the scientific, for it displayed the economic man, Hobbes’s hero, come to life and a respectable member of society.  With him came the growth of political economy, apparently the first really scientific study of man.  From Political Economy Darwin borrowed the conception of the struggle for existence and the survival of the fittest, and from the new biology the doctrine of Evolution through individual competition returned to reinforce with the prestige of the new science the economists’ conception of society.

For the first half of the nineteenth century all the forces inspiring individualism seemed to work together, for economics and biology breathed a benevolent optimism which promised that if the scientific forces of individualism were left to work unchecked by state restriction, they would of themselves produce that individual liberty and free development which idealistic individualism desired.

The development of the industrial revolution, however, soon made economic optimism impossible, and with its decay idealistic and scientific individualism parted company.  The former retained its concern for individual liberty but came to see that its ideal was as much threatened by economic dependence as by state control, that the choice for most members of society was not one between state interference and no interference at all, but between the state controlling or not controlling the power of interference possessed by the economically superior members of society.  On such principles Henry Sidgwick justified an extensive system of state control of industry, and for such reason the strongest supporters of the rights of the individual have been found among Socialists.

Scientific individualism, which found its unit in the economic man and sought to absorb in economics both ethics and politics, was not in essence affected by the discrediting of economic optimism.  It painted the struggle between individuals in gloomy instead of in attractive colours, its ‘scientific’ prepossessions inclined it to a determinism which led easily to the economic theory of history and even, by a curious conversion of opposites, to the ‘scientific socialism’ of Karl Marx.  In its essence it is a denial of the real existence of politics.  For it is a theory of society which denies the possibility of a will for the common good and therefore the possibility of political ideals.