Heidegger on the abyss

‘The word for abyss – Abgrund – originally means the soil and ground toward which, because it is undermost, a thing tends downward. But in what follows we shall think of the Ab- as the complete absence of the ground... But because presence conceals itself at the same time, it is itself already absence. Thus the abyss holds and remarks everything... In his hymn ‘The Titans’ Holderlin says of the Abgrund that it is ‘all-perceiving’. He among mortals who must, sooner than other mortals and otherwise than they, reach into the abyss, comes to know the marks that the abyss remarks. For the poet, these are the traces of the fugitive gods.'

 From 'What Are Poets For?'


 nb 'grunden' also mean 'to found'- so this void-space is also a constitutive space