Terry Teachout on Billie Holiday; full of praise, in general, but ends with this: 

"To romanticize self-destructive behavior is always a mistake, even when it is the behavior of a great artist--and it is an even bigger mistake to take such behavior as a sign of greatness."

Clive James on his Latest Readings. Includes this quotation from Joseph Conrad: 

"...peace is not a principle, it is only a desirable state of affairs, and can't be obtained without a capacity for violence at least equal to the violence of the threat."