 While all commentators take the passage at B17.1–13 (=D 73.233–244) as fundamental, their interpretations vary, sometimes widely. In the traditional sort of interpretation (see O’Brien 1969, Wright 1981) this passage speaks about a two-part symmetrical cosmic cycle, which endlessly repeats itself. We can trace the history of one cycle, beginning with the point at which all the roots are united, completely intermingled and motionless under the total domination of Love, an image reminiscent of Parmenides’ spherical “what-is”. Then Strife enters and begins to separate the roots out, until finally all are completely separated into distinct, self-contained masses of fire, air, earth and water. At this point, Love begins to unite the roots until, once again, they are completely intermingled and another cycle begins. In each half of the cycle, as the separation or unification proceeds, there is a cosmogony (generation of a cosmos or ordered world) and a zoogony (generation of animals). In the first half-cycle, under the increasing influence of Strife, a cosmos and then animals come to be. In the second half, under the increasing influence of Love, again a cosmos and animals come to be. We will start with the traditional interpretations which hold that there are double cosmogonies and then look at the second strain of interpretations where there is only one cosmogony.