From Johann Wolfgang von Goethe: "Against criticism a man can neither protest not defend himself; he must act in spite of it, and then it will gradually yield to him."
Benajmin Disraeili: "How much easier it is to be critical than to be correct."
Edith Wharton: "After all, one knows one's weak points so well, that it's rather bewildering to have the critics overlook them and invent others."
Kurt Vonnegut: "Any reviewer who expresses rage and loathing for a novel is preposterous. He or she is like a person who has put on full armor and attached a hot fudge sundae."
Robert Burns, to a particular critic:"Thou eunuch of language: thou butcher, imbruing thy hands in the bowels of orthography: thou arch-heretic in pronunciation: thou pitch-pipe of affected emphasis: thou carpenter, mortising the awkward joints of jarring sentences: thou squeaking dissonance of cadence: thou pimp of gender: thou scape-gallows from the land of syntax: thou scavenger of mood and tense: thou murderous accoucheur of infant leanings: thou ignis fatuus, misleading the steps of benighted ignorance: thou pickle-herring in the puppet-show of nonsense."
That one is my favorite. I found it via a guest blog by DC poet Kim Roberts. Thanks, Kim!