These lines were already referred to Pythagoras by Timaios (Diog. viii. 54). As we are told (Diog. _ib._) that some referred the verses to Parmenides, it is clear that no name was given. Footnote 578: On frs. 138 and 143 see Vahlen on Arist. _Poet._ 21. 1547 b 13, and Diels in _Hermes_, xv. p. 173. [Sidenote: Empedokles and Parmenides.] 106. At the very outset of his poem, Empedokles is careful to mark the difference between himself and previous inquirers. He speaks angrily of those who, though their experience was only partial, professed to have found the whole (fr. 2); he even calls this “madness” (fr. 4). No doubt he is thinking of Parmenides. His own position is not, however, sceptical. He only deprecates the attempt to construct a theory of the universe off-hand instead of trying to understand each thing we come across “in the way in which it is clear” (fr. 4). And this means that we must not, like Parmenides, reject the assistance of the senses. Weak though they are (fr. 2), they are the only channels through which knowledge can enter our minds at all. We soon discover, however, that Empedokles is not very mindful of his own warnings. He too sets up a system which is to explain everything, though that system is no longer a monistic one. It is often said that this system was an attempt to mediate between Parmenides and Herakleitos. It is not easy, however, to find any trace of specially Herakleitean doctrine in it, and it would be truer to say that it aimed at mediating between Eleaticism and the senses. He repeats, almost in the same words, the Eleatic argument for the sole reality and indestructibility of “what _is_” (frs. 11-15); and his idea of the “Sphere” seems to be derived from the Parmenidean description of the universe as it truly is.[579] Parmenides had held that the reality which underlies the illusory world presented to us by the senses was a corporeal, spherical, continuous, eternal, and immovable _plenum_, and it is from this that Empedokles starts. Given the sphere of Parmenides, he seems to have said, How are we to get from it to the world we know? How are we to introduce motion into the immovable _plenum_? Now Parmenides need not have denied the possibility of motion within the Sphere, though he was bound to deny all motion of the Sphere itself; but such an admission on his part, had he made it, would not have served to explain anything. If any part of the Sphere were to move, the room of the displaced matter must at once be taken by other matter, for there is no empty space. This, however, would be of precisely the same kind as the matter it had displaced; for all “that _is_” is one. The result of the motion would be precisely the same as that of rest; it could account for no change. But, Empedokles must have asked, is this assumption of perfect homogeneity in the Sphere really necessary? Evidently not; it is simply the old unreasoned feeling that existence must be one. If,