When a person dies their body (matter) remains and their mind extinguishes. That is observed. Under no circumstances does matter extinguish. It only changes. Conservation is observed. This consistency and predictability of matter is essential to my understanding (call it reason if you will). From nowhere else does my knowledge of the reality start except from the sensation, then perception and conception of it.
When I die, I will not continue as a mind or spirit but the matter will transform into something else that may or may not have a mind.