It is sometimes said, though less often now than it used to be, that philosophers have no special role to play in public affairs, since most public issues depend primarily on an assessment of facts. On questions of fact, it is said, philosophers as such have no special expertise, and so it has been possible to engage in philosophy without committing oneself to any position on major public issues. No doubt there are some issues of social policy and foreign policy about which it can truly be said that a really expert assessment of the facts is required before taking sides or acting, but the issue of famine is surely not one of these. The facts about the existence of suffering are beyond dispute. Nor, I think, is it disputed that we can do something about it, either through orthodox methods of famine relief or through population control or both. This is therefore an issue on which philosophers are competent to take a position. The issue is one which faces everyone who has more money than he needs to support himself and his dependents, or who is in a position to take some sort of political action. These categories must include practically every teacher and student of philosophy in the universities of the Western world. If philosophy is to deal with matters that are relevant to both teachers and students, this is an issue that philosophers should discuss.
Discussion, though, is not enough. What is the point of relating philosophy to public (and personal) affairs if we do not take our conclusions seriously? In this instance, taking our conclusion seriously means acting upon it. The philosopher will not find it any easier than anyone else to alter his attitudes and way of life to the extent that, if I am right, is involved in doing everything that we ought to be doing. At the very least, though, one can make a start. The philosopher who does so will have to sacrifice some of the benefits of the consumer society, but he can find compensation in the satisfaction of a way of life in which theory and practice, if not yet in harmony, are at least coming together.
(Peter Singer, "Famine, Affluence, and Morality," Philosophy & Public Affairs 1 [spring 1972]: 229-43, at 242-3)
Reasonable, adj. Accessible to the infection of our own opinions. Hospitable to persuasion, dissuasion and evasion.
(Ambrose Bierce, The Devil's Dictionary, c. 1911)