Hatred is increased by being reciprocated, and can on the other hand be destroyed by love.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

““ He who conceives that the object of his hate is destroyed will feel pleasure. ” “ If we conceive that anyone takes delight in something, which only one person can possess, we shall endeavour to bring it about, that the man in question shall not gain possession thereof. ” Hatred is increased by being reciprocated, and can on the other hand be destroyed by love. The last two books of the Ethics, entitled respectively “ Of human bondage, or the strength of the emotions ” and “ Of the power of the understanding, or of human freedom, ” are the most interesting. We are in bondage in proportion as what happens to us is determined by outside causes, and we are free in proportion as we are self-determined.” source