For every animal is naturally formed to fly and abhor things that appear hurtful, and the causes of them; and to pursue and admire those which appear beneficial, and the causes of them. It is impractical, then, that one who supposes himself to be hurt should be happy about the person who, he thinks, hurts him, just as it is impossible to be happy about the hurt itself.
 Epictetus, Enchiridion (125). copy citation

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Author Epictetus
Source Enchiridion
Topic hurting animal
Date 125
Language English
Reference
Note Translated by Elizabeth Carter
Weblink http://classics.mit.edu/Epictetus/epicench.html

Context

“For if you suppose any of the things not in our own control to be either good or evil, when you are disappointed of what you wish, or incur what you would avoid, you must necessarily find fault with and blame the authors. For every animal is naturally formed to fly and abhor things that appear hurtful, and the causes of them; and to pursue and admire those which appear beneficial, and the causes of them. It is impractical, then, that one who supposes himself to be hurt should be happy about the person who, he thinks, hurts him, just as it is impossible to be happy about the hurt itself. Hence, also, a father is reviled by a son, when he does not impart to him the things which he takes to be good; and the supposing empire to be a good made Polynices and Eteocles mutually enemies. On this account the husbandman, the sailor, the merchant, on this account those who lose wives and children, revile the gods.” source