McWhorter, J. PhD Linguistics (Stanford). The Power of Babel (2003). p. 32 Bottom.
Semantic drift has an especially visible effect on combinations of roots and prefixes or suffixes, and this effect, too, creates important differences between a language and the one it turns into. Our French sentence’s admettez-le “ admit it” is a good example of this kind of development. Admettre is composed of ad-, a preservation of the full word or prefix for “to” in Latin, and mettre “ to put.” This verb had an ancestor in Latin, but this Latin verb admittere did not mean “ to confess,” which was conveyed with other verbs like agnoscere. Instead, the main meaning of admittere was the literal one of “ putting or sending into.” 'The “ confess” meaning of its French descendant arrived gradually by the same kind of hanging implication that created French’s have-perfect: to admit something is to give it entree into—that is, “put it into”—your acknowledged awareness. [My emboldening]
I understand that “admettre” originally signfied “put to”, but how did it generalize to: put to “your acknowledged awareness”? The author doesn't expound.
Put to itself doesn't suggest “your acknowledged awareness”. One can “put to” many other things, if this makes sense. So what narrowed put to to “your acknowledged awareness”?