“If men were rational in their conduct, that is to say, if they acted in the way most likely to bring about the ends that they deliberately desire, intelligence would be enough to make the world almost a paradise. In the main, what is in the long run advantageous to one man is also advantageous to another.
But men are actuated by passions which distort their view; feeling an impulse to injure others, they persuade themselves that it is to their interest to do so. They will not, therefore, act in the way that is in fact to their own interest unless they are actuated by generous impulses which make them indifferent to their own interest. This is why the heart is as important as the head. By the “heart” I mean, for the moment, the sum-total of kindly impulses. (…)
And so we come back to the old dilemma: only kindliness can save the world, and even if we knew how to produce kindliness we should not do so unless we were already kindly. Failing that, it seems that the solution which the Houynhnms adopted towards the Yahoos, namely extermination, is the only one; apparently the Yahoos are bent on applying it to each other.”