PHILOSOPHY.- Valentine Rose's verdict, "Plotinus and Aristotle, that is the whole of Arab philosophy," is not quite true of the philosophy of Ibn Sînâ. As in life, so in thought, the Persian Muslim tried to combine two utterly incompatible things: in the latter, Muslim orthodoxy with Neo-Platonic, emanational Aristotelianism, or even with Persian and Hindu mysticism. To the orthodox he wished to appear orthodox; to the philosophers, a philosopher of the popular, Aristotelian sort; and to the Mazdeans, a Mazdean mystic,- being in reality it seems the last. Like Scotus Erigena and others, he believes that revelation, being a mere anticipation of philosophy for the benefit of the masses, must be interpreted by philosophy in accordance with the laws of reason. His chief merit as a philosopher is that he makes clear and systematic what Aristotle had left dark and confused; and this he does chiefly through Neo-Platonic conceptions. Accepting from Aristotle the classification of Being into necessary, actual, and possible, he spreads it over his geocentric universe, and classifies the sciences according to it. At the summit of this universe is the necessary Being, God, the subject of Metaphysics; at the other end are sublunary things, merely possible, the subject of Physics; and between the two are things possible made necessary by the first cause, and therefore actual,-the spheres and their moving intelligences, the subject of Mathematics, i. e., Arithmetic, Geometry, Music, Mechanics, Optics (cf. Dante, 'Banquet,' ii. 14, 15). He seeks to combine the Aristotelian doctrine of the (derived) eternity of matter and the world with Neo-Platonic emanationism, holding the latter to be a timeless process. The Supreme Being being one, can produce but one thing, the First Intelligence or Word; but this, having a triple consciousness, (1) of God, (2) of its own actuality, (3) of its own possibility, produces by the first, the Second Intelligence; by the second, the first spheral soul; and by the third, the first moving sphere, as the body to this soul. This process goes on, producing ever greater and greater multiplicity, until the sphere of the moon is reached (cf. Dante, 'Paradise,' ii. 112 seq.). Here is produced finally the "active intellect" (see Aristotle, 'De Anima,' iii. 5, 1), and the physical world with its manifold souls, including the human. The human soul is not actually, but merely potentially intelligent, being dependent for actual thought upon the "active intellect," which is thus the same for all men; just as the sun is the same for all colors. In the sublunary world prevails generation, whose function is to prepare souls for the action of the "active intellect." This action, like that of the spheral intelligences, is not physical, but like that which. a beloved object exerts upon a lover (see Aristotle, 'Metaph.' xi. 7: 10726 3). Hence there prevails throughout the universe not only an outward action from God down to the lowest extremity of being, but also an inward return action, due to love, up to God (see Dante,

'Paradise,' i. 103 seq.). This is the Ma'dd, (sometimes translated Resurrection, Hereafter!) which plays so important a part in subsequent thought, giving the practical formula for mysticism. Through love, any soul may rise above sublunary matter from sphere to sphere, until at last it loses itself in the superessential unity of God,- the Nirvana of Buddhism (cf. Dante, Paradise,' as a whole). Though holding these pantheistic emanational views, Ibn Sînâ maintains the immortality of the individual soul; a fact hardly due to deference for Muhammad, since in spite of him he pointedly denies the resurrection. of the body and maintains the freedom of the will. How he reconciled the latter view with his belief in sphere influences is hard to see.

Ibn Sînâ's general view of the world and of man's relation to it is on the whole Neo-Platonic. In logic he follows Aristotle and Al Fârâbî, but champions a conceptualist doctrine of universals. He is the author of the favorite scholastic maxim, "It is the intellect that gives universality to the forms of thought» (Intellectus in formis agit universalitatem). In Psychology he gives definiteness and system to the doctrines of Aristotle, and has some original views, e. g. on the psychology of prophecy. He thinks that whereas man generally derives his knowledge from the phantasms of the senses, as illuminated by the "active intellect," in certain extraordinary cases the process is reversed. Then the "active intellect," under the influence of God, rouses phantasms, and these are the stuff of prophecy (see Dante, 'Purgatory,' xvii. 13 seq.).

The influence of Ibn Sînâ upon the thought of the Middle Age, among Arabs, Jews, and Christians alike, was wide and deep. Men like Albertus Magnus and Thomas Aquinas, while cursing Ibn Rushd (Averroës), spoke of Ibn Sînâ with respect, perhaps because he maintained the immortality of the soul. Yet he was bitterly attacked on all sides: by the Muslim orthodox Al Gazâlî and heterodox Ibn Rushd, by the Jewish Maimonides, and by Christian thinkers generally. Especially obnoxious were his doctrines of (1) the eternity of the world, which conflicted with the orthodox notions of creation, and (2) the unity of the "active intellect," which seemed to preclude the freedom and responsibility of man. It was against these, especially as formulated by Ibn Rushd, that the chief efforts of scholasticism in its best period were directed. And though these efforts were formally successful, yet the influence of the great Persian remained and remains. It may be said that Dante's great poem is soaked in it, and it had much to do with the great heretical movements of the Middle Age, from the days of Joachim of Floris onward. It lives even to-day.