Social Hygiene in Relation to the Alleged Opposition between Socialism and Individualism--The Two Parties in Politics--The Relation of Conservatism and Radicalism to Socialism and Individualism--The Basis of Socialism--The Basis of Individualism--The seeming Opposition between Socialism and Individualism merely a Division of Labour--Both Socialism and Individualism equally Necessary--Not only Necessary but Indispensable to each other--The Conflict between the Advocates of Environment and Heredity--A New Embodiment of the supposed Conflict between Socialism and Individualism--The Place of Eugenics--Social Hygiene ultimately one with the Hygiene of the Soul--The Function of Utopias. The controversy between Individualism and Socialism, the claim of the personal unit as against the claim of the collective community, is of ancient date. Yet it is ever new and constantly presented afresh. It even seems to become more acute as civilization progresses. Every scheme of social reform, every powerful manifestation of individual energy, raise anew a problem that is never out of date. It is inevitable, indeed, that with the development of social hygiene during the past hundred years there should also develop a radical opposition of opinion as to the methods by which such hygiene ought to be accomplished. There has always been this opposition in the political sphere; it is natural to find it also in the social sphere. The very fact that old-fashioned politics are becoming more and more transformed into questions of social hygiene itself ensures the continuance of such an opposition. In politics, and especially in the politics of constitutional countries of which England is the type, there are normally two parties. There is the party that holds by tradition, by established order and solidarity, the maintenance of the ancient hierarchical constitution of society, and in general distinguishes itself by a preference for the old over the new. There is, on the other side, the party that insists on progress, on freedom, on the reasonable demands of the individual, on the adaptation of the accepted order to changing conditions, and in general distinguishes itself by a preference for the new over the old. The first may be called the party of structure, and the second the party of function. In England we know the adherents of one party as Conservatives and those of the other party as Liberals or Radicals.