Why is "Usted" grammatically a third person?

Question

In English polite form of address is "You" which is second person singular and plural. In Russian it is "Вы" which is plural second person. In Spanish (and probably French and Italian) polite address is the third person. Why so?

Answer 1

You never could talk to the king by addressing him as "YOU". That was talk for the commoners. It was "YOUR MAJESTY" or "YOUR ROYAL HIGHNESS" as if there were a 3rd person in the room with you and the king. In our courts, you address the judge as "YOUR HONOR" never directly with YOU.

Answer 2

Interesting question. To clarify, in English "you" is used for the second person singular and plural, in both polite and informal/casual/even rude contexts. Basically, English has much less formal structure in general.

In Spanish, my hunch is that Usted being a third person is because often you are referring to that person as Usted because speaking indirectly is more formal. You would be using this person's title (Dra. Ramos, Sr. Rivero, Srta. Diaz, etc), not their first name, so you in that formal, indirect space both communicatively and grammatically. Think about, even in English, in older films and plays, if a servant is speaking to their boss, they speak in the third person many times, such as "would the doctor like a cup of tea?", even though they are speaking to the doctor. It seems that when the situation calls for more deference, speaking directly seems too blunt or rude, too assuming of closeness for the relationship.

Does that help?