James Thurber - Guide to Modern English

From: James Thurber’s: Ladies’ and Gentlemen’s Guide to Modern English Usage. - Hope this is of help…

“The indefinite “one” is another source of trouble and is frequently the cause of disagreeable scenes. Such a sentence as “One loves one’s friends” is considered by some persons to be stilted and over-formalized, and such persons insist that “One loves his friends” is permissible. It is not permissible, however, because “one” is indefinite and “his” is definite and the combination is rhetorically impossible. This is known as hendiadys and was a common thing in Latin. Rare examples of it still exist and are extremely valuable as antiques, although it is usually unsafe to sit or lie down on one.”

You can find more extended excerpts here:

• Who and Whom