Demanding that one's sources should have really existed is so wildly ad hominem...
Mr Lévy admitted last night that he had been fooled by Botul, the creation of a literary journalist, Frédéric Pages, but he was not exactly contrite.
Appearing on Canal+ television, he said he had always admired The Sex Life of Immanuel Kant and that its arguments were solid, whether written by Botul or Pages. "I salute the artist [Pages]," he said, adding with a philosophical flourish: "Hats off for this invented-but-more-real-than-real Kant, whose portrait, whether signed Botul, Pages or John Smith, seems to be in harmony with my idea of a Kant who was tormented by demons that were less theoretical than it seemed."
In all seriousness, it's a fair point: for influential, even dominant conceptions of how to go about doing philosophy, either the arguments are valid or they aren't, and that's pretty much that. The question of whether Botul is a decent philosopher (which is to say, whether the analyses produced in his name stack up) isn't altogether like that of whether Lieutenant Kizhe was a competent soldier in battle. As Pessoa once put it:
Needless to say, I agree with certain parts of [the heteronyms'] theories, and disagree with other parts. But that's quite beside the point. If they write beautiful things, those things are beautiful, regardless of any and all metaphysical speculations about who 'really' wrote them. If in their philosophies they say true things... those things are true regardless of the intention or 'reality' of whoever said them.