Philosophy ought to question the basic assumptions of the age. Thinking through, critically and carefully, what most people take for granted is, I believe, the chief task of philosophy, and it is this task that makes philosophy a worthwhile activity. Regrettably, philosophy does not always live up to its historic role. Philosophers are human beings and they are subject to all the preconceptions of the society to which they belong. Sometimes they succeed in breaking free of the prevailing ideology: more often they become its most sophisticated defenders.
(Peter Singer, "All Animals Are Equal," Philosophic Exchange 5 [1974]: 103-27, at 111)
