Afterlife? No, no, no. When we are dead our souls cross to the Maker's side. If we're good, we spend the rest of eternity basking in His presence.

[That wasn't science, that was religion. In his own way, Dorian was a devout Andrastian.]

Spirits and Demons aren't human and never were. Or elf or dwarf or Qunari, come to that. They are native to the Fade. Studying them can tell us about the Fade, about magic. About how it all works. Studying them allows us a greater understanding of ourselves and our interactions with the Fade.