These hapless caricaturists of the dialectic of Plato, and the logic of Aristotle, careless of any vital principles or real results, ready enough to use fallacies each for their own party, and openly proud of their success in doing so, were assisted by worthy compeers of an outwardly opposite tone of thought, the Cyrenaics, Theodorus and Hegesias. With their clique, as with their master Aristippus, the senses were the only avenues to knowledge; man was the measure of all things; and “happiness our being’s end and aim.” Theodorus was surnamed the Atheist; and, it seems, not without good reason; for he taught that there was no absolute or eternal difference between good and evil; nothing really disgraceful in crimes; no divine ground for laws, which according to him had been invented by men to prevent fools from making themselves disagreeable; on which theory, laws must be confessed to have been in all ages somewhat of a failure. He seems to have been, like his master, an impudent light-hearted fellow, who took life easily enough, laughed at patriotism, and all other high-flown notions, boasted that the world was his country, and was no doubt excellent after-dinner company for the great king. Hegesias, his fellow Cyrenaic, was a man of a darker and more melancholic temperament; and while Theodorus contented himself with preaching a comfortable selfishness, and obtaining pleasure, made it rather his study to avoid pain. Doubtless both their theories were popular enough at Alexandria, as they were in France during the analogous period, the Siècle Louis Quinze. The “Contrat Social,” and the rest of their doctrines, moral and metaphysical, will always have their admirers on earth, as long as that variety of the human species exists for whose especial behoof Theodorus held that laws were made; and the whole form of thought met with great approbation in after years at Rome, where Epicurus carried it to its highest perfection. After that, under the pressure of a train of rather severe lessons, which Gibbon has detailed in his “Decline and Fall of the Roman Empire,” little or nothing was heard of it, save _sotto voce_, perhaps, at the Papal courts of the sixteenth century. To revive it publicly, or at least as much of it as could be borne by a world now for seventeen centuries Christian, was the glory of the eighteenth century. The moral scheme of Theodorus has now nearly vanished among us, at least as a confessed creed; and, in spite of the authority of Mr. Locke’s great and good name, his metaphysical scheme is showing signs of a like approaching disappearance. Let us hope that it may be a speedy one; for if the senses be the only avenues to knowledge; if man be the measure of all things; and if law have not, as Hooker says, her fount and home in the very bosom of God himself, then was Homer’s Zeus right in declaring man to be “the most wretched of all the beasts of the field.”