Indefinite pronoun (Cf. she and he are definite).
Originally Posted by Unregistered
As a pronoun, one
can also function in an impersonal, objective manner, standing for the writer or for all people who are like the writer or for the average person or for all people who belong to a class. In the United States, one
sometimes has a literary or highfalutin feel to it; the more it is used, the more pretentious it feels. In British English, the use of the impersonal or generic one
is more commonplace and has no such stigma. In the U.S., one
is often replaced by you.
- One would think the airlines would have to close down.
- One would [You'd] think the inner dome of heaven had fallen.
- The young comedian was awful; one felt embarrased for him.
- If one fails, then one must try harder next time.
Source On the Uses of One