John Stuart Mill
(1806 - 1873)

"It may not be superfluous to notice a few more of the common misapprehensions of utilitarian ethics, even those which are so obvious and gross that it might appear impossible for any person of candour and intelligence to fall into them; since persons, even of considerable mental endowments, often give themselves so little trouble to understand the bearings of any opinion against which they entertain a prejudice, and men are in general so little conscious of this voluntary ignorance as a defect, that the vulgarest misunderstandings of ethical doctrines are continually met with in the deliberate writings of persons of the greatest pretensions both to high principle and to philosophy."
J S Mill
(Utilitarianism)