Superior powers of mind and profound study are of no use, if they do not sometimes lead a person to different conclusions from those which are formed by ordinary powers of mind without study
 John Stuart Mill, Considerations on Representative Government (1861). copy citation

Context

“and jointly therewith, to obtain, in the greatest measure possible, for the function of government, the benefits of superior intellect, trained by long meditation and practical discipline to that special task. If this second purpose is worth attaining, it is worth the necessary price. Superior powers of mind and profound study are of no use, if they do not sometimes lead a person to different conclusions from those which are formed by ordinary powers of mind without study; and if it be an object to possess representatives in any intellectual respect superior to average electors, it must be counted upon that the representative will sometimes differ in opinion from the majority of his constituents, and that when he does, his opinion will be the oftenest right of the two.” source