To prove that Christianity is the only true philosophy, the Apologists asserted that it alone guaranteed correct knowledge and true holiness here and hereafter. They proclaimed its preëminence because it is a perfect revelation of God through Jesus Christ. Since man is imprisoned in the world of the senses and ruled by dæmons, he can never be saved except through a perfect revelation. To be saved is to become rational, and man can become rational only by divine aid. Revelation has not been restricted to Christianity, but God’s inspiration has been at work in all mankind. The truth in Socrates, Plato, and Pythagoras has not been their own, but has sprung from this same divine inspiration, for truth never is the product of man’s unaided reason. Socrates and Plato got their truth in part from God’s direct revelation to them, in part indirectly from reading the works of Moses and the prophets. But revelation outside of Christianity has not been complete nor continuous. The first perfect revelation was in Jesus Christ, for He is the first to reveal the divine Logos completely. He is the first in whom the Logos has become man. He is the Son of God because the complete essence of the inexpressible Deity is unfolded in Him. The Apologists thus identified reason and revelation. The Logos is the same in revelation, nature, or history. The Stoic conception of the Logos, which Philo had stripped of its materialistic character, was identified with Christ and revelation. Justin could regard as inspired what the Greeks had looked upon as natural in their own doctrines. Christ is the world-reason, in whom the divine has been incarnated, and the Apologists had the enormous advantage over the neo-Platonists of being able to point to Jesus as the definite and historical incarnation of God. The Apologists could summon the prevailing Platonic dualism of God and matter to their aid in showing the need of such a revelation; for matter is altogether without reason and goodness. Thus a summary of their doctrine is as follows: the world is bad and needs a revelation; the Logos of God has always been present in history, but has especially appeared in Jesus Christ, the man, in order to redeem men from their sin and establish the kingdom of God.