In view of this practical pessimism, Socrates is the archetype of the theoretical optimist, who in the above-indicated belief in the fathomableness of the nature of things, attributes to knowledge and perception the power of a universal medicine, and sees in error and evil. To penetrate into the depths of the nature of things, and to separate true perception from error and illusion, appeared to the Socratic man the noblest and even the only truly human calling: just as from the time of Socrates onwards the mechanism of concepts, judgments, and inferences was prized above all other capacities as the highest activity and the most admirable gift of nature. Even the sublimest moral acts, the stirrings of pity, of self-sacrifice, of heroism, and that tranquillity of soul, so difficult of attainment, which the Apollonian Greek called Sophrosyne, were derived by Socrates, and his like-minded successors up to the present day, from the dialectics of knowledge, and were accordingly designated as teachable. He who has experienced in himself the joy of a Socratic perception, and felt how it seeks to embrace, in constantly widening circles, the entire world of phenomena, will thenceforth find no stimulus which could urge him to existence more forcible than the desire to complete that conquest and to knit the net impenetrably close. To a person thus minded the Platonic Socrates then appears as the teacher of an entirely new form of "Greek cheerfulness" and felicity of existence, which seeks to discharge itself in actions, and will find its discharge for the most part in maieutic and pedagogic influences on noble youths, with a view to the ultimate production of genius. But now science, spurred on by its powerful illusion, hastens irresistibly to its limits, on which its optimism, hidden in the essence of logic, is wrecked. For the periphery of the circle of science has an infinite number of points, and while there is still no telling how this circle can ever be completely measured, yet the noble and gifted man, even before the middle of his career, inevitably comes into contact with those extreme points of the periphery where he stares at the inexplicable. When he here sees to his dismay how logic coils round itself at these limits and finally bites its own tail--then the new form of perception discloses itself, namely _tragic perception,_ which, in order even to be endured, requires art as a safeguard and remedy. If, with eyes strengthened and refreshed at the sight of the Greeks, we look upon the highest spheres of the world that surrounds us, we behold the avidity of the insatiate optimistic knowledge, of which Socrates is the typical representative, transformed into tragic resignation and the need of art: while, to be sure, this same avidity, in its lower stages, has to exhibit itself as antagonistic to art, and must especially have an inward detestation of Dionyso-tragic art, as was exemplified in the opposition of Socratism to Æschylean tragedy.