Hume wrote some of his works in the style of a Dialogue following Platos lead; has any-one since? Or is it all prose?
See John Perry's A Dialogue on Personal Identity and his Dialogue on Good, Evil and the Existence of God. Furthermore some of David Lewis's smaller pieces (written together with Stephanie Lewis) are dialogues: 'Holes' and a review of Casati and Varzi's Holes and Other Superficialities
Here are a few examples of books using the dialogue form:
- Worlds Apart: A Dialogue of the 1960's by Owen Barfield (1963) is written in the form of a fictional dialogue.
- Corydon by André Gide (1911) contains four Socratic dialogues on homosexuality.
- Peter Kreeft published several books that are fictional dialogues between Socrates and a more recent philosopher, e.g. Socrates Meets Hume, Socrates Meets Kant, Socrates Meets Machiavelli.
This seems to have survived more in logic and foundations than philosophy broadly.
Lakatos Proofs and Refutations on the philosophy of science as applied to mathematics is not so out-of-date. Neither are various books like Surreal Numbers by Knuth, or some of Raymond Smulliyan. Large parts of Douglas Hoffstadter's Godel, Escher, Bach are in dialog form.
I think the form is coming to be restricted to popularizations or restatements of work that is kind of impenetrable otherwise.
Matthew Stewart did a little bit in his book: The Truth About Everything: An Irreverent History of Philosophy.