If I could make sense of that question, I might be able to answer it. When you say "base", do you mean "basis" or are you referring to the linguistic root or stem of the word? And by "supposition", do you mean "presupposition" or "assumption"?
In the original post where I used the word "non-physical", I was saying that there appeared to be nothing in brain activity that would suggest a supernatural or spiritual basis for brain activity. Does that help?
I would also add, in light of your remarks to idav, that nobody is claiming that the mind is programmed like a computer is programmed. Think of a brain as an autonomous device that programs itself. Our DNA serves as the blueprint for the construction of this machine. What caused our DNA to have a set of these instructions was billions of years of optimization through adaptation to environmental changes affecting the slightly flawed mechanism of self-replication encoded in DNA.