Martin Heidegger, existentialist and a phenomenologist, had raised the interest of modern scholars toward the thinking of ancient creek philosophers from a totally new perspective. From the study of beings, pursued by metaphysics from antiquity to modern times, Heidegger set the crucial question in way that he understood it was meant by pre-Socratic philosophers. That is - what is being in itself? Being without beings!

Heidegger refers to Parmenides and to his poem On Nature, where Parmenides learns from the Goddess of Night the two ways to knowledge. The way of gods – aletheia, and the way of mortal humans – doxa. The way of gods is to know that everything is one. The way of mortals is knowledge about sensible things and this is always knowledge about opposites in nature phenomena.