The oldest thread begins in language and perhaps before language, with a commonness-of-mind among members of a tribe or social group. Untested by dialogue-not yet brought out "into the open" in this way-this commonness-of-mind is tested and effec- tive nonetheless in the coordinated behavior of the group around a set of beliefs held simply to be "the case:" beliefs about the environment, about the magnitude and location of its dangers and rewards, what is wise and foolhardy, and about what lies beyond; about the past, the future, about what lies within opaque things, over the horizon, under the earth, or above the sky. The answers to all these questions, always "wrong," and always pictured in some way, are common property before they are privately internalized and critiqued.
Language to explain the outside world but not my world. My mind is my world and my mind has its own language different from your mind's language different enough that we have trouble explaining things to each other trouble feeling together and not alone all the time. I know I feel alone.
The commonness of mind you say we have is there I suppose- the grass is green to you and me... if only I could remember the last time I saw grass.