Elizabeth Sewell, Paul Valéry (1952)

Then there is Mallarmé himself, sitting, as he admitted in a letter to a close friend, in front of a mirror as he wrote, to make sure that he would not disappear into that nothingness which during the writing of Hérodiade his soul had seen and shuddered at.

It is like Mallarmé, whose poetry is so pure that it is about poetry and nothing else at all, a form commenting on a form, the content irrelevant [via].