All thought starts from the ordinary dualism or pluralism which conceives of the world as consisting of the juxtaposition of mutually independent things and persons.
The Sophistes shows among other things that an identity-philosophy breaks down into a dualism of thought and expression, when it applies the predicate of unity to the real, just as the absolute pluralism on the other hand collapses into unity if it affirms or admits any form of relation whatsoever.
The parochial clergy were probably in a healthier condition; but the old abuses of pluralism and non-residence were as rampant as ever, and though their work may have been in many cases honorably carried out, it is certain that energy and intelligence were at a low ebb.
The aim of knowledge is explanation, and the dualism or pluralism which acquiesces in recognizing two or more wholly disparate forms of reality has in so far renounced explanation (see Dualism).
Diogenes (q.v.) began by insisting on the necessity of there being only one principle of things, herein contradicting the pluralism of Heraclitus.
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.