However dogmatic a system of philosophical enquiry may appear to us, it must have been preceded by a criticism of the observed facts of experience. The details of the criticism and the processes of self-argumentation by which the thinker arrived at his theory of the Universe might indeed be suppressed, as being relatively unimportant, but a thoughtful reader would detect them as lying in the background behind the shadow of the general speculations, but at the same time setting them off before our view. An Aristotle or a Patañjali may not make any direct mention of the arguments which led him to a dogmatic assertion of his theories, but for a reader who intends to understand them thoroughly it is absolutely necessary that he should read them in the light as far as possible of the inferred presuppositions and inner arguments of their minds; it is in this way alone that he can put himself in the same line of thinking with the thinker whom he is willing to follow, and can grasp him to the fullest extent. In offering this short study of the Pātañjala metaphysics, I shall therefore try to supplement it with such of my inferences of the presuppositions of Patañjali’s mind, which I think will add to the clearness of the exposition of his views, though I am fully alive to the difficulties of making such inferences about a philosopher whose psychological, social, religious and moral environments differed so widely from ours.