Even cursory reflection on the etymology of common words reveals the process, the "change in the center of gravity" (RM 232) of human consciousness, which Barfield designates as "interiorization" or (sometimes) "internalization." Contemplating quintessential Renaissance words like "influence," "humour," "melancholy," and "temper," he concludes in History in English Words,
    It seems for the moment as though some invisible sorcerer had been conjuring them all inside ourselves--sucking them away from our own warm flesh and blood, down into the shadowy realm of thoughts and feelings. There they still repose; astrology has changed to astronomy; alchemy to chemistry; today the cold stars glitter unapproachable overhead, and with a naive detachment mind watches matter moving incomprehensibly in the void. At last, after four centuries, thought has shaken herself free. (138)
Our subjectivity, we must conclude, has been "extracted," beginning in prehistory:
    If history has been par excellence the period of developing thought, prehistory was par excellence the period of developing language--the period of the original emergence of speaker's meaning from lexical meaning, the period therefore during which man was slowly and painfully extracting his subjectivity from language; that is, as Cassirer, for one, has so convincingly demonstrated, from the inside of nature through the medium of language. . . . "Man was extracting . . ." it was said, but since the very thing he was extracting was his own subjectivity, he ought not to have been the subject of a sentence at all. "The period during which man's subjectivity was being extracted . . ." would have been more accurate, if less elegant. (SM 110-11)
"Where is the spirit which has been drained away from nature?" Barfield asks. "Within ourselves" (RCA 217). "Pan," Barfield notes, "has shut up shop. But he has not retired from business; he has merely gone indoors. Or, in the well-known words of Coleridge:
    We receive but what we give
    And in our life alone does Nature live. (SA 130)
Interiorization, "self-consciousness by exclusion" (RM 86), is also observable in Wordsworth's "Immortality Ode." As the "Shades of the prison-house begin to close/Upon the growing Boy," the poet tells us, we nevertheless retain our memory of original participation:
in a season of calm weather
Though inland far we be,
Our souls have sight of that immortal sea
Which brought us hither. (quoted in RM 87)
"Both ontogenetically and phylogenetically," Barfield reminds in Speaker's Meaning,
    subjectivity is never something that was developed out of nothing at some point in space, but is a form of consciousness that has contracted from the periphery into individual centers. Phylogenetically, it becomes clear to us that the task of Homo sapiens, when he first appeared as a physical form on earth, was not to evolve a faculty of thought somehow out of nothing, but to transform the unfree wisdom, which he experienced through his organism as given meaning, into the free subjectivity that is correlative only to active thought, to the individual activity of thinking. (113-14)
Donne was wrong; we are islands, at least at this stage in the evolution of consciousness--as Sanderson insists in Worlds Apart, again citing the German philosopher Ernst Cassirer:
    Between his receptor system and his effector system (which he shares with the animals) man has this "symbolic system," as Cassirer calls it. What is its function? Its function is to create that aesthetic "distance" between himself and the world, which is the very thing that constitutes his humanity. It is what frees him from the world. He is no longer a peninsula pushed out by natural forces. He is a separated island existing in a symbolic universe. Physical reality recedes in proportion as his symbolic activity advances. He objectivizes more and more completely. But the symbols were the product of his own inner activity in the first place and they never really lose that character, however completely his very success in objectifying them may make him forget the fact. Forever afterwards, in dealing with things he is, as Cassirer puts it, "in a sense conversing with himself." (47)
See in particular "Subject and Object in the History of Meaning" (SM 92-118), Unancestral Voice, passim, What Coleridge Thought, passim.