That's crossing into metaphysics, which isn't usually a welcome topic here, but the fact remains that more than 80% of the current and prior world population believes/believed in a non-material reality.
The persistence and stickiness of that belief throughout history ought to at least make us sit up and pay attention. Something's going on, and it's not a mere historic lack of scientific rigor, notwithstanding science's penchant for filling gaps people previously attributed to spiritual causes. That near-universal reflex to attribute things to spiritual causes in the first place is what's interesting - why do people not merely say the cause is "something physical we don't understand"?
