Mat 15:11 That which goes into the mouth does not defile a man; but that which comes out of the mouth, this defiles a man.

What if the word translated in the above verse doesnt' mean "defile" at all, but something else entirely? The word translated above as "defile" is koinoô, which means "to make common," "to communicate," and "to impart." "To make common" doesn't mean, as it does in English, "to make lower-class," but more in the sense of "to share." The word also means "to partner" and "to come to terms with." Only here in Matthew is it translated as "defile," which as far as I can see, has nothing to do with the original intent of the Greek. I believe this is an example of a word getting filtered through through the feudal era sensitivity, which looked down upon all things "common."

Alternative translation: That which goes into one mouth does not share a man, but what comes out of the mouth, this is what communicates a man.

Symbolic version (mouth=mind): That which goes into the mind is not shared with others, but what comes out of the mind is what is shared with others.