This fundamental homogeneity of primitive culture, however, must not be made the excuse for a treatment at the hands of psychology and sociology that dispenses with the study of details and trusts to an a priori method.
Otto Stoll's studies in Guatemala, Berendt's in Central America, Ernst's in Venezuela, Im Thurn's in Guiana, those of Ehrenreich, von den Steinen, Meyer in Brazil, or of Bandelier, Bastian, Briihl, Middendorf, von Tschudi in Peru, afford the historian of comparative sociology ample groundwork for a comprehensive grasp of South American tribes.
On the other hand, many of his ideas have passed into the common literary stock, and have been more precisely elaborated by later writers on sociology and history; and though his own work is now somewhat neglected, its influence was immensely valuable in provoking further research and speculation.
In philosophy and science he was an amateur, seeking to found a new sociology and a Utopian polity out of his own inner consciousness and study of nature, of poetry and the Bible.
It is an exaggeration of the theory which makes it an explanation of all human life, but the whole science of dynamic sociology rests upon the postulate of Marx.
In the Principles of Sociology Spencer's most influential ideas have been that of the social organism, of the origination of religion out of the worship of ancestral ghosts, of the natural antagonism between nutrition and reproduction, industrialism and warfare.
Ethics here stands to sociology in a close relation, similar, in many respects, to that which we find in Hegel and in Comte.
Finally, apart from these more academic arguments there is an undoubted paradox in a theory which, at a moment when in whatever direction we look the best inspiration in poetry, sociology and physical science comes from the idea of the unity of the world, gives in its adhesion to pluralism on the ground of its preponderating practical value.
The Pali books written in Ceylon, Burma and Siam will be our best and oldest, and in many respects our only, authorities for the sociology and politics, the literature and the religion, of their respective countries.