"The dog has an enviable mind; it remembers the nice things in life and quickly blots out the nasty."

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It is just like man's vanity and impertinence to call an animal dumb because it is dumb to his dull perceptions. Heaven is by favor; if it were by merit your dog would go in and you would stay out. Of all the creatures ever made he (man) is the most detestable. Of the entire brood, he is the only one...that possesses malice. He is the only creature that inflicts pain for sport, knowing it to be pain. The fact that man knows right from wrong proves his intellectual superiority to the other creatures; but the fact that he can do wrong proves his moral inferiority to any creature that cannot.

— Mark Twain