But setting aside the doctrine that self-sacrifice is a religious duty, there remains the doctrine that it is a measure of expediency, that when the strong help the weak they also help themselves. Let it be said at once that this second doctrine, provided only it be applied intelligently and without any admixture of sentimentality, is not in opposition to anything in Nietzsche's philosophy. On the contrary, he is at pains to point out the value of exploiting the inefficient masses, and obviously that exploitation is impossible without some concession to their habits and desires, some offer, however fraudulent, of a _quid pro quo_--and unprofitable unless they can be made to yield more than they absorb. For one thing, there is the business of keeping the lower castes in health. They themselves are too ignorant and lazy to manage it, and therefore it must be managed by their betters. When we appropriate money from the public funds to pay for vaccinating a horde of negroes, we do not do it because we have any sympathy for them or because we crave their blessings, but simply because we don't want them to be falling ill of smallpox in our kitchens and stables, to the peril of our own health and the neglect of our necessary drudgery.[3] In so far as the negroes have any voice in the matter at all, they protest against vaccination, for they can't understand its theory and so they see only its tyranny, but we vaccinate them nevertheless, and thus increase their mass efficiency in spite of them. It costs something to do the work, but we see a profit in it. Here we have a good example of self-sacrifice based frankly upon expediency, and Nietzsche has nothing to say against it.