Taken together, they reflect a lively, unselfconscious, rigorous, erudite and earnestly open mind that's busy refining its view of life, literature and a great deal in between. Delightful, painful and spontaneously funny…
Lively, rigorous, erudite, unselfconscious, earnestly open-minded, delightful, painful, spontaneously funny: not a bad set of adjectives.
I am always interested in how you can describe really talented people. "Smart" has been overused to be devoid of meaning. The most original and descriptive adjective from the above list is: unselfconscious.
Here's my review of Smith's On Beauty.