The phrase "man of letters" means-

Man of letters - A scholar/author

The phrase "man of letters" refers to a person who is well-versed in many subjects, particularly in literature and scholarly pursuits.

This term is typically used to describe someone who is knowledgeable in the humanities, including literature, philosophy, and sometimes history. A "man of letters" is often a writer, critic, or scholar who has a broad and deep understanding of these fields. The term does not literally refer to someone who likes philosophical ideas, issues letters, or is appointed by a letter, but rather to someone with a deep and extensive engagement with the literary and intellectual world.