If Epicurus and his followers underrated logic, to natural science they attached a considerable value. This value was, however, exclusively derived from a sense of the practical advantages which a knowledge of nature confers in opposing superstition. Without such an object the study of nature would have seemed wholly superfluous. [1149] Such being their attitude of mind, the Epicureans were, as might have been expected, indifferent about giving a complete and accurate explanation of phenomena. Their one aim was to put forward such a view of nature as would do away with the necessity for supernatural intervention, without at the same time pretending to offer a sufficient solution of the problems raised by science. [1150] Whilst, therefore, he devoted considerable attention to natural science, [1151] Epicurus does not seem to have considered certainty to be of importance, or even to be possible, in dealing with details of scientific study. Of the general causes of things we can and ought to entertain a firm conviction, since the possibility of overcoming religious prejudices and the fears occasioned by them depends on these convictions. No such result, however, follows from the investigation of details, which, on the contrary, only tends to confirm prejudices in those who are not already emancipated from them. In dealing with details, therefore, it is enough for Epicurus to show that various natural causes for phenomena may be imagined, and to offer various suggestions which dispense with the intervention of the Gods and the myths of a belief in Providence. [1152] To say that any one of these suggestions is the only possible one, is in most cases to exceed the bounds of experience and human knowledge, and to go back to the capricious explanations of mythology. [1153] Possibly the world may move, and possibly it may be at rest. Possibly it may be round, or else it may be triangular, or have any other shape. Possibly the sun and the stars may be extinguished at setting, and be lighted afresh at rising. It is, however, equally possible that they may only disappear under the earth and reappear again, or that their rising and setting may be due to yet other causes. Possibly the waxing and waning of the moon may be caused by the moon’s revolving; or it may be due to an atmospheric change, or to an actual increase and decrease in the moon’s size, or to some other cause. Possibly the moon may shine with borrowed light, or it may shine with its own, experience supplying us with instances of bodies which give their own light, and of those which have their light borrowed. [1154] From these and such-like statements it appears that questions of natural science in themselves have no value for Epicurus. Whilst granting that only one natural explanation of phenomena is generally possible, yet in any particular case he is perfectly indifferent which explanation is adopted. [(2) Mechanical explanation of nature.]