It is not useful, but hurtful, that the constitution of the country should declare ignorance to be entitled to as much political power as knowledge.
 John Stuart Mill, Considerations on Representative Government (1861). copy citation

Context

“I look upon it as only relatively good; less objectionable than inequality of privilege grounded on irrelevant or adventitious circumstances, but in principle wrong, because recognizing a wrong standard, and exercising a bad influence on the voter's mind. It is not useful, but hurtful, that the constitution of the country should declare ignorance to be entitled to as much political power as knowledge. The national institutions should place all things that they are concerned with before the mind of the citizen in the light in which it is for his good that he should regard them; and as it is for his good that he should think that every one is entitled to some influence, but the better and wiser to more than others, it is important that this conviction should be professed by the state, and embodied in the national institutions.” source