Great stress is, however, laid by him on the general explanation. In contrast with the religious view which regards the world as a system of means leading to ends, the leading business of the natural science of the Epicureans is to refer all phenomena to natural causes. To an Epicurean nothing appeals more absurd than to suppose that the arrangements of nature have for their object the well-being of mankind, or that they have any object at all. The tongue is not given us for the purpose of speaking, nor the ears for the purpose of hearing. As a matter of fact, it would, indeed, be more correct to say, that we speak because we have a tongue, and hear because we have ears. Natural powers have acted purely according to the law of necessity, and among their various products there could not fail to be some presenting the appearance of purpose in their arrangement. In the case of man there have resulted many such products and powers. But this result is by no means intentional; it is an accidental consequence of natural causes. In explaining nature all thought of Gods must be put out of sight. For their happiness would be inconceivable, on the supposition that they cared for man and his welfare. [1155] Confining his interest in nature, as Epicurus did, entirely to this general view of things, he was all the more inclined, in carrying it into details, to rely upon some older system. No system, however, appeared to correspond better with his tone of mind than that of Democritus, which, moreover, commended itself to him not only by absolutely banishing the idea of final cause, but by referring everything to matter, and by its theory of atoms. As Epicurus places in each individual thing taken by itself the ultimate end of action, so Democritus had theoretically made all that is real to consist in what is absolutely individual or in atoms. His natural science, therefore, seemed to present the most natural basis for the Epicurean Ethics. If the Stoics, in their views of nature, closely followed Heraclitus, Epicurus in his followed Democritus still more closely, and hence, with the exception of one single point, the additions made by Epicurus to the theory of this philosopher are of no philosophical importance. [(3) Atoms and empty space.]