Asking, in the next place, what idea must be formed of the arrangement of the world, we are met by the two principles which Epicurus is never weary of inculcating; one, that we must explain nothing as an intentional arrangement by deity, but refer everything simply and solely to mechanical causes; the other, that in explaining phenomena the widest possible room must be given for hypotheses of every kind, and that nothing is more absurd than to abridge the wide range of possible explanations by exclusively deciding in favour of any one. [1195] Thereby the investigation of nature loses for him its value as such, nor is it of any great interest to us to follow his speculations on nature into detail. On one point he dogmatises, protesting that the framework of heaven must not be considered the work of God, [1196] nor must life and reason be attributed to the stars. [1197] Otherwise, on nearly all the questions which engaged the attention of astronomers at that time, he observes the greatest indifference, treating the views of his predecessors, good and bad alike, with an easy superficiality which can only be explained by supposing him altogether indifferent [1198] as to their truth. The state of his own astronomical knowledge can, moreover, be easily seen by recalling the notorious assertion [1199] that the sun, the moon, and the stars are either not at all, or only a little larger, and may possibly be even less than they appear to be. The Epicureans also thought to support their theory that the earth, borne by the air, reposes in the middle of the world—a theory which on their hypothesis of the weight of bodies is impossible [1200]—by the gradual diminution in weight of the surrounding bodies. [1201] It would be impossible here to go through the treatment which they gave to atmospheric and terrestrial phenomena, particularly as the principle already indicated was most freely used, and many explanations were given as being all equally possible. [1202] [(4) Plants and animals.] Out of the newly made earth plants at first grew, [1203] and afterwards animals came forth, since the latter, according to Lucretius, can by no possibility have fallen from heaven. [1204] In other worlds, likewise, living beings came into existence, though not necessarily in all. [1205] Among these beings were originally, as Empedocles had previously supposed, [1206] all sorts of composite or deformed creatures. Those, however, alone continued to exist which were fitted by nature to find support, to propagate, and to protect themselves from danger. Romantic creatures, such as centaurs of chimæras, can never have existed here, because the beings of which they are compounded would require conditions of life [1207] altogether different. [C. Mankind.] [(1) Origin of the human race.]