madness

Wikipedia says that

“Although Blake was considered mad by contemporaries for his idiosyncratic views, he is held in high regard by later critics for his expressiveness and creativity, and for the philosophical and mystical undercurrents within his work.”

I wonder whether this is anything like a useful opposition, in the sense that I doubt most “later critics” would make a case for Blake’s sanity as a necessary condition for his “expressiveness and creativity, and for the philosophical and mystical undercurrents within his work.”