When there is no difference of opinion, differences merely of taste may be sufficient to detract greatly from the happiness of married life.
 John Stuart Mill, The Subjection of Women (1869). copy citation

Context

“but in general this source at least of dissension is got rid of, by reducing the minds of women to such a nullity, that they have no opinions but those of Mrs. Grundy, or those which the husband tells them to have. When there is no difference of opinion, differences merely of taste may be sufficient to detract greatly from the happiness of married life. And though it may stimulate the amatory propensities of men, it does not conduce to married happiness, to exaggerate by differences of education whatever may be the native differences of the sexes. If the married pair are well-bred and well-behaved people, they tolerate each other's tastes;” source