See Patin, _Heraklits Einheitslehre_ (1886). To Patin undoubtedly belongs the credit of showing clearly that the unity of opposites was the central doctrine of Herakleitos. It is not always easy, however, to follow him when he comes to details. Footnote 372: Philo, _Rer. Div. Her._ 43 (R. P. 34 c). [Sidenote: The One and the Many.] 68. Anaximander had taught already that the opposites were separated out from the Boundless, but passed away into it once more, so paying the penalty for their unjust encroachments on one another. It is here implied that there is something wrong in the war of opposites, and that the existence of the Many is a breach in the unity of the One. The truth which Herakleitos proclaimed was that there is no One without the Many, and no Many without the One. The world is at once one and many, and it is just the “opposite tension” of the Many that constitutes the unity of the One. The credit of having been the first to see this is expressly assigned to Herakleitos by Plato. In the _Sophist_ (242 d), the Eleatic stranger, after explaining how the Eleatics maintained that what we call many is really one, proceeds:— But certain Ionian and (at a later date) certain Sicilian Muses remarked that it was safest to unite these two things, and to say that reality is both many and one, and is kept together by Hate and Love. “For,” say the more severe Muses, “in its division it is always being brought together” (cf. fr. 59); while the softer Muses relaxed the requirement that this should always be so, and said that the All was alternately one and at peace through the power of Aphrodite, and many and at war with itself because of something they called Strife. In this passage the Ionian Muses stand, of course, for Herakleitos, and the Sicilian for Empedokles. We remark also that the differentiation of the one into many, and the integration of the many into one, are both eternal and simultaneous, and that this is the ground upon which the system of Herakleitos is contrasted with that of Empedokles. We shall come back to that point again. Meanwhile we confine ourselves to this, that, according to Plato, Herakleitos taught that reality was at once many and one.