From John Ruskin's Modern Painting:
It is not as the creating, but as the seeing man, that we are here contemplating the master of the true grotesque. It is because the dreadfulness of the universe around him weighs upon his heart that his work is wild; and therefore through the whole of it we shall find the evidence of deep insight into nature. His beasts and birds, however monstrous, will have profound relations with the true. He may be an ignorant man, and little acquainted with the laws of nature; he is certainly a busy man, and has not much time to watch nature; but he never saw a serpent cross his path, nor a bird flit across the sky, nor a lizard bask upon a stone, without learning so much of the sublimity and inner nature of each as will not suffer him thenceforth to conceive them coldly. He may not be able to carve plumes or scales well; but his creatures will bite and fly, for all that. The ignoble workman is the very reverse of this. He never felt, never looked at nature; and if he endeavor to imitate the work of the other, all his touches will be made at random, and all his extravagances will be ineffective; he may knit brows, and twist lips, and lengthen beaks, and sharpen teeth, but it will all be in vain. He may make his creatures disgusting, but never fearful.
On a completely unrelated note, I wrote about reading as part of The Laughing Yeti series "Writers on Reading." You can read my entry here.