A system thus based upon severe mathematical considerations, and taking as its starting-point a vacuum and atoms--the former actionless and passionless; which considers the production of new things as only new aggregations, and the decay of the old as separations; which recognizes in compound bodies specific arrangements of atoms to one another; which can rise to the conception that even a single atom may constitute a world--such a system may commend itself to our attention for its results, but surely not to our approval, when we find it carrying us to the conclusions that even mathematical cognition is a mere semblance; that the soul is only a finely-constituted form fitted into the grosser bodily frame; that even for reason itself there is an absolute impossibility of all certainty; that scepticism is to be indulged in to that degree that we may doubt whether, when a cone has been cut asunder, its two surfaces are alike; that the final result of human inquiry is the absolute demonstration that man is incapable of knowledge; that, even if the truth be in his possession, he can never be certain of it; that the world is an illusive phantasm, and that there is no God. [Sidenote: Legends of Democritus.] I need scarcely refer to the legendary stories related of Democritus, as that he put out his eyes with a burning-glass that he might no longer be deluded with their false indications, and more tranquilly exercise his reason--a fiction bearing upon its face the contemptuous accusation of his antagonists, but, by the stolidity of subsequent ages, received as an actual fact instead of a sarcasm. As to his habit of so constantly deriding the knowledge and follies of men that he universally acquired the epithet of the laughing philosopher, we may receive the opinion of the great physician Hippocrates, who being requested by the people of Abdera to cure him of his madness, after long discoursing with him, expressed himself penetrated with admiration, and even with the most profound veneration for him, and rebuked those who had sent him with the remark that they themselves were the more distempered of the two. [Sidenote: Rise of philosophy in European Greece.] [Sidenote: Commercial communities favourable to new ideas.]