Having decided to compose the work, he continues, I divided the subject into ten fundamental principles, and devoted a section of the book to each principle. I endeavored to write in a plain and easy style, omitting difficult expressions, technical terms and demonstrations in the manner of the dialecticians. I had to make an exception in the first section dealing with the existence and unity of God, where the sublet of the subject required the employment of logical and mathematical proofs. For the rest I made use of comparisons or similes, adduced support from the Bible and tradition, and also quoted the sages of other nations.[111] We have already seen in the introduction that Bahya was indebted for his ideas to the ascetic and Sufic literature of the Arabs, and Yahuda, who is the authority in this matter of Bahya's sources, has shown recently that among the quotations of the wise men of other nations in Bahya's work are such as are attributed by the Arabs to Jesus and the gospels, to Mohammed and his companions, to the early caliphs, in particular the caliph Ali, to Mohammedan ascetics and Sufis.[112] In selecting the ten general and inclusive principles, Bahya lays down as the first and most fundamental the doctrine of the deity, or as it is called in the works of the Kalam, the Unity. As God is a true unity, being neither substance nor accident, and our thought cannot grasp anything except substance or accident, it follows that we cannot know God as he is in himself, and that we can get a conception of him and of his existence from his creatures only. The second section is therefore devoted to an examination of creation. Then follow in order sections treating of the service of God, trust in God, action for the sake of God alone, submission to God, repentance, self-examination, separation from the pleasures of the world, love of God. In his discussion of the unity of God, Bahya follows the same method as Saadia, and the Kalam generally, _i. e._, he first proves that the world must have been created; hence there must be a creator, and this is followed by a demonstration of God's unity. The particular arguments, too, are for the most part the same, as we shall see, though differently expressed and in a different order. The important addition in Bahya is his distinction between God's unity and other unities, which is not found so strictly formulated in any of his predecessors, and goes back to Pseudo-Pythagorean sources in Arabian literature of Neo-Platonic origin. In order to prove that there is a creator who created the world out of nothing we assume three principles. First, nothing can make itself. Second, principles are finite in number, hence there must be a first before which there is no other. Third, every composite is "new," _i. e._, came to be in time, and did not exist from eternity.