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.
I mentioned to a friend that perhaps there are physical or material things only. He said that is rather naive.
If I were to take the impermanence seriously, then even physical things (like mental things) do not exist as such. What is to say the appearance of things seemingly longer than thought is not as immaterial as thought itself. Just because the length of appearance is longer and seemingly more permanent does not mean it is permanent. So there is justification that things are not real as well.
I have come to the conclusion that nothing exists except for the physical world. The mind is a product of an object, namely an body. A personality is a product of the mind. This evidentially converges with the Buddhist concept of non-self (anatta). To me, what is called the ‘self’ is not what it seems. It may be considered a kind of illusion.