Abstract The great german Scholar, Eduard Zeller, suggested that the reference to male and female in Parmenides B12.5-6 was probably an allusion to the physical principles of `mortal opinion': Night and Light. This suggestion has been rejected by some scholars because such an association would lead us to admit that, in B12, male was associated with Night and female with Light, a theory which would be at odds with the supposed misogyny of Greek culture. However, Parmenides' account of `mortal opinion' (...) certainly associates male with coldness and density, the attributes of Night, and female with hotness and greater rarity, the attibutes of Light. The aims of this paper are, then, first, to show that the association of female with Light and of male with Night is in fact right; and secondly to investigate the main dualistic features of Parmenides' `mortal opinion' (embryology, sleep, death, knowledge) in relation to this theme. This will lead us, finally, to focus our attention on the Proem, which introduces us to a world full of female divinities, among whom - beyond the gates of the ways of day and night - is the unnamed goddess who will initiate her young male auditor into the two `ways'. (shrink)