Abbot Zerchi smiled thinly. “You don’t have a soul, Doctor. You are a soul. You have a body, temporarily.”
In simpler times, Hell would take a soul on the death of the body. Death is more complicated in Fallen London, though not unknown. So it's not terribly uncommon to meet someone who's short a soul. Some of them become mumbling, dead-eyed husks: some of them simply turn to occupations where soullessness is a professional advantage.
— An informational text snippet from Fallen London
What do you think the soul is? Some pie you can slice? The soul can be bludgeoned, tortured, but never broken. Not even by me.
Today, you got a hard look behind the curtain. Wrecking the natural order's not quite such fun when you have to mop up the mess, is it? This is hard for you, Dean. You throw away your life because you've come to assume that it'll bounce right back into your lap. But the human soul is not a rubber ball. It's vulnerable, impermanent, but stronger than you know. And more valuable than you can imagine. So - I think you've learned something today.
Harry: I'm sure of one thing now that I wasn't before.
Harry: Souls. I mean, you always wonder if they're real. Even if you believe in them, you still have to wonder: Is my existence just this body? Is there really something more? Do I really have a soul?
Uriel: You've got it backwards, Harry. You are a soul. You have a body.