which came more and more into vogue from the tenth century onwards. Add to this that he wrote Persian and Arabic at will, and you get the picture of a most accomplished man. His life was superabundantly rich both in work and in enjoyment. In geniality, of course he was inferior to his older compatriot, the poet Firdausi (940–1020), and in scientific talent to his contemporary Beruni (v. infra § 9), men still of importance in our eyes. Ibn Sina, however, was the true expression of his time; and upon this fact have been founded his great influence and historic position. He did not, like Farabi, withdraw from common life to become immersed in the commentators of Aristotle, but he blended in himself Greek science and Oriental wisdom. Enough commentaries, he thought, had already been written on the ancient authors: it was now time for men to construct a philosophy of their own,—in other words, to give a modern form to the ancient doctrines. 3. In Medicine Ibn Sina gives diligent endeavour to produce a systematic account of that science, but here he proves by no means an exact logician. He assigns a large place, at least theoretically, to Experience, and describes in detail the conditions under which alone, for example, the efficacy of remedies can be ascertained. But the philosophical principles which are involved in Medicine, must be taken over in the form of lemmas from Philosophy itself. Philosophy proper is divided into Logic, Physics and Metaphysics. In its entirety it embraces the science of all Existence as such, and of the principles of all the separate sciences, whereby, as far as is humanly possible, the Soul which is devoted to philosophy, attains the highest perfection. Now Existence is either spiritual, when it is the subject of Metaphysics, or corporeal, when it is discussed in Physics, or intellectual, when it forms the theme of Logic. The subjects of Physics can neither exist, nor be thought of as existing, without Matter. The Metaphysical, however is quite devoid of Matter; while the Logical is an abstraction from the Material. The Logical has a certain likeness to the Mathematical, in so far as the subjects of Mathematics may also be abstractions from matter. But yet the Mathematical always remains capable of being represented and constructed, while on the other hand the Logical, as such, has its existence only in the intellect, as, for instance, Identity, Unity and Plurality, Universality and Particularity, Essentiality and Contingency, and so on. Consequently Logic is the Science of the Determinate Forms of Thought.