Personal pronoun to address another person.
That I can address you by "you" and you can address me in the same way
is a familiar fact of speech since one learned to speak. Even so, it
normally involves assumptions that, though also quite ordinary, are
quite far going:
That there are other persons, who have their own
and beliefs; that you are an
entity that is rather like me, and can be to
a considerable extent understood from my own experiences, just as my own
experiences can be to a considerable
extent understood from your experiences.
The reason this is a far going
assumption, even though every human being is raised using it, is
that the experiences of others are not given to us. And indeed, Berkeley
uses especially this fact in his Alciphron to try to justify the
assumption of God, along the line of "If you admit other people's
experiences exist, even if all you see of them is their external
behaviour, then why not admit that God exists?"