another will conceive his enemy as the cause of some evil or pain; thus he will be affected with pain or fear, accompanied by the idea of his enemy as cause; in other words, he will be affected with hatred towards his enemy, as I said above.
Corollary I.—He who conceives, that one whom he loves hates him, will be a prey to conflicting hatred and love. For, in so far as he conceives that he is an object of hatred, he is determined to hate his enemy in return. But, by the hypothesis, he nevertheless loves him: wherefore he will be a prey to conflicting hatred and love.
Corollary II.—If a man conceives that one, whom he has hitherto regarded without emotion, has done him any injury from motives of hatred, he will forthwith seek to repay the injury in kind.
Proof.—He who conceives, that another hates him, will (by the last proposition) hate his enemy in return, and (III. xxvi.) will endeavour to