From Nacho’s comment here:
Here’s something else to discuss:
Impermanence, as a mark of existence, truly slices through notions of the persistence of anything (this does not mean obduracy of our imaginations nor of what we deem real), just that its nature is flux, not solidity, nor unchangingness. Hence, no self exists because we have impermanence. This business of impermanence renders the world full of suffering (this is what Lacan calls Lack). These condition each other in the here and now.
My friend the Christian Platonist would object, ‘yes, but there still must be some thing that is impermanent’… I’m not quite sure how to convince him that his objection misses the mark. Even early Buddhist schools quarraled over the nature of dharmas (the smallest consitutents of existence) in their Abhidharma literature. Nagarjuna seems to have swept aside their quarrels with a few stanzas in his Madhyamakakarika, but still not everyone is satisfied.