Secondly , he claimed that Dark matter provides room for a deity and a soul, no way, because dark matter can still be inferred from gravitational lensing, and it has mass the same way that ordinary matter has, it just doesn't emit visible radiation.
Thirdly, he was talking about multiple dimensions, well, each brane basically is an image of the other branes, so there cannot be a disjoint afterlife.
The bugger even wrote a book on the "evidence" for an afterlife

These arguments can be found in the Boteach,D'Souza, Taleb vs Harris, Hitchens and Dennett debate, a link to which exists somewhere on this board.