Style is in no way an embellishment, as certain people think, it is not even a question of technique; it is, like colour with certain painters, a quality of vision, a revelation of a private universe which each one of us sees and which is not seen by others. The pleasure an artist gives us is to make us know an additional universe. How, under these conditions, do certain writers declare that they try not to have a style? I don't understand it. I hope that you will make them understand my explanations.
Proust, it seems, read the contents of this letter when he was interviewed a year later by the journalist Élie-Joseph Bois for Le Temps. Interestingly, the last three sentences, which constitute (to my reading) a direct challenge to Gide's own approach, were omitted in the interview.
I would say that they still stand as a challenge to any of us writing now.