It is highly interesting to note how the Persian mind gradually got rid of the Emanation theory of Neo-Platonism, and reached a purer notion of Plato's Philosophy. The Arab Muhammadans of Spain, by a similar process of elimination reached, through the same medium (Neo-Platonism) a truer conception of the Philosophy of Aristotle--a fact which illustrates the genius of the two races. Lewes in his Biographical History of Philosophy remarks that the Arabs eagerly took up the study of Aristotle simply because Plato was not presented to them. I am, however, inclined to think that the Arab genius was thoroughly practical; hence Plato's philosophy would have been distasteful to them even if it had been presented in its true light. Of the systems of Greek philosophy Neo-Platonism, I believe, was the only one which was presented in its completeness to the Muslim world; yet patient critical research led the Arab from Plotinus to Aristotle, and the Persian to Plato. This is singularly illustrated in the Philosophy of Mulla Hādī, who recognises no Emanations, and approaches the Platonic conception of the Real. He illustrates, moreover, how philosophical speculation in Persia, as in all countries where Physical science either does not exist or is not studied, is finally absorbed by religion. The "Essence", i.e. the metaphysical cause as distinguished from the scientific cause, which means the sum of antecedent conditions, must gradually be transformed into "Personal Will" (cause, in a religious sense) in the absence of any other notion of cause. And this is perhaps the deeper reason why Persian philosophies have always ended in religion. Let us now turn to Mulla Hādī's system of thought. He teaches that Reason has two aspects:--(a) Theoretical, the object of which is Philosophy and Mathematics, (b) Practical, the object of which is Domestic Economy, Politics, etc. Philosophy proper comprises the knowledge of the beginning of things, the end of things, and the knowledge of the Self. It also includes the knowledge of the law of God--which is identical with religion. In order to understand the origin of things, we should subject to a searching analysis the various phenomena of the Universe. Such an analysis reveals that there are three original principles.[178:1] (1). The Real--Light. (2). The Shadow. (3). The not-Real--Darkness. [178:1] Asrār al-Ḥikam; p. 6.