This is the principle that distinguishes Socrates from the other leaders of the Greek Illumination. While he was imbued with the motives of the Greek culture of his time,――curious about its results, feeling its usefulness, and critical of all tradition,――he nevertheless withheld himself from its skeptical conclusions. Any culture illumination runs the danger of defeating itself and becoming skeptical of its own powers. This is what actually happened in the Sophistic philosophy. But when Socrates set himself against this superficial and self-destructive outcome of his age, he became in his constructive philosophy the clearest and most comprehensive expression of that age. Because he grasped the principle of the Greek Enlightenment deeply and formulated it constructively, his intellectual reign became historically established. The fundamental principle of the philosophy of Socrates was therefore the real principle of classic Greek civilization, and by saving that principle he saved Greek civilization for modern Europe. =The Unsystematic Character of the Socratic Philosophy.= The casual reader is often troubled to know for what precisely Socrates is searching. The vagueness of the Socratic quest is partly due to the fact that he had no system. Indeed, he had no groundwork for a system of thought. His psychology or theory of the human mind was undefined. He speaks of sensations and perceptions, but they, with the feelings and the will, are considered by him to be unimportant factors in the conscious life. On the whole, the mind was thought by him to be an aggregation of conceptions or ideas. The feelings cloud the activity of these conceptions, and the only feeling to which Socrates attached any importance was his dæmon or divine voice. This grew to be his mentor as he grew older. Socrates never made a scientific psychological analysis. He began rather with three assumptions which amounted to convictions. They were these: _that only by acquiring conceptions is true knowledge to be found_; _that virtue consists in acting according to conceptions_; _that the world has been designed according to conceptions_. Conceptions were, so to speak, an obsession with Socrates.[18] They were his postulates, his instruments, and his goal. The other factors of the mind were neglected by him.