4. Upon the contact of the Jew with Greek philosophy doubt arose in many minds, and belief entered into conflict with reason. But even then, the defense of the faith was still carried on by reasoning along the lines of common sense.(161) Thus the regularity of the sun, moon, and stars,—all worshiped by the pagans as deities—was considered a proof of God’s omnipotence and rule of the universe, a proof which the legend ascribes to Abraham in his controversy with Nimrod.(162) In like manner, the apocryphal Book of Wisdom(163) says that true wisdom, as opposed to the folly of heathenism, is “to reason from the visible to the Invisible One, and from the cosmos, the great work of art, to the Supreme Artificer.” 5. Philo was the first who tried to refute the “atheistic” views of materialists and pantheists by adducing proofs of God’s existence from nature and the human intellect. In the former he pointed out order as evidence of the wisdom underlying the cosmos, and in the latter the power of self-determination as shadowing forth a universal mind which determines the entire universe.(164) Still, with his mystical attitude, Philo realized that the chief knowledge of God is through intuition, by the inner experience of the soul. 6. Two proofs taken from nature owe their origin to Greek philosophy. Anaxagoras and Socrates, from their theory of design in nature, deduced that there is a universal intelligence working for higher aims and purposes. This so-called _teleological_ proof, as worked out in detail by Plato, was the unfailing reliance of subsequent philosophers and theologians.(165) Plato and Aristotle, moreover, from the continuous motion of all matter, inferred a prime cause, an unmoved mover. This is the so-called _cosmological_ proof, used by different schools in varying forms.(166) It occupies the foremost place in the systems of the Arabic Aristotelians, and consequently is dominant among the Jewish philosophers, the Christian scholastics, and in the modern philosophic schools down to Kant. It is based upon the old principle of causality, and therefore takes the mutability and relativity of all beings in the cosmos as evidence of a Being that is immutable, unconditioned, and absolutely necessary, causa sui, the prime cause of all existence.