The ancient Epicureans argued against the existence of the Deity, because they held that the existence of Evil either proved him to be limited in power or of a malignant nature; either of which imperfections is inconsistent with the first notions of a divine being.

In this kind of reasoning they have been followed both by the atheists and sceptics of later times.

Bayle regarded the subject of evil as one of the great arsenals from whence his weapons were to be chiefly drawn. None of the articles in his famous Dictionary are more labored than those in which he treats of this subject. Monichian, and still more Paulician, almost assume the appearance of formal treatises upon the question; and both Marchionite and Zoroaster treat of the same subject. All these articles are of considerable value; they contain the greater part of the learning upon the question; and they are distinguished by the acuteness of reasoning which was the other characteristic of their celebrated author.

Those ancient philosophers who did not agree with Epicurus in arguing from the existence of evil against the existence of a providence that superintended and influenced the destinies of the world, were put to no little difficulty in accounting for the fact which they did not deny, and yet maintaining the power of a divine ruler. The doctrine of a double principle, or of two divine beings of opposite natures, one beneficent, the other mischievous, was the solution which one class of reasoners deemed satisfactory, and to which they held themselves driven by the phenomena of the universe.

Others unable to deny, the existence of things which men denominate evil, both physical and moral, explain them in a different way. They maintained that physical evil only obtains the name from our imperfect and vicious or feeble dispositions; that to a wise man there is no such thing; that we may rise superior to all such groveling notions as make us dread or repine at any events which can befall the body; that pain, sickness, loss of fortune or of reputation, exile, death itself, are only accounted ills by a weak and pampered mind; that if we find the world tiresome, or woeful, or displeasing, we may at any moment quit it; and that therefore we have no right whatever to call any suffering connected with existence on earth an evil, because almost all sufferings can be borne by a patient and firm mind; since if the situation we are placed in becomes either intolerable, or upon the whole more painful than agreeable, it is our own fault that we remain in it.

But these philosophers took a further view of the question which especially applied to moral evil. They considered that nothing could be more groundless than to suppose that if there were no evil there could be any good in the world; and they illustrated this position by asking how we could know anything of temperance, fortitude or justice, unless there were such things as excess, cowardice and injustice.

These were the doctrines of the Stoics, from whose sublime and impracticable philosophy they seemed naturally enough to flow. Aulus Gellius relates that the last-mentioned argument was expounded by Chrysippus, in his work upon providence. The answer given by Plutarch seems quite sufficient: “As well might you say that Achilles could not have a fine head of hair unless Thersites had been bald; or that one man’s limbs could not be all sound if another had not the gout.”

In truth, the Stoical doctrine proceeds upon the assumption that all virtue is only the negative of vice; and is as absurd, if indeed it be not the very same absurdity, as the doctrine which should deny the existence of affirmative or positive truths, resolving them all into the opposite of negative propositions. Indeed, if we even were to admit this as an abstract position, the actual existence of evil would still be unnecessary to the idea, and still more to the existence, of good. For the conception of evil, the bare idea of its possibility, would be quite sufficient, and there would be no occasion for a single example of it.

The other doctrine, that of two opposite principles, was embraced by most of the other sects, as it should seem, at some period or other of their inquiries. Plato himself, in his later works, was clearly a supporter of the system; for he held that there were at least two principles, a good and an evil; to which he added a third, the moderator or mediator between them.

Whether this doctrine was, like many others, imported into Greece from the East, or was the natural growth of the schools, we cannot ascertain. Certain it is that the Greeks themselves believed it to have been taught by Zoroaster in Asia, at least five centuries before the Trojan war; so that it had an existence there long before the name of philosophy was known in the western world.