There can be no fanatics in the cause of genuine liberty. Fanaticism is excessive zeal. There may be, and have been fanatics in false religion – in the bloody religions of the heathen. There are fanatics in superstition. But there can be no fanatic, however warm their zeal, in the true religion, even although you sell your goods and bestow your money on the poor, and go on and follow your Master. There may, and every hour shows around me, fanatics in the cause of false liberty – that infamous liberty which justifies human bondage, that liberty whose ‘corner-stone is slavery.’ But there can be no fanaticism however high the enthusiasm, in the cause of rational, universal liberty – the liberty of the Declaration of Independence.
Thaddeus Stevens, “The California Question” (June 10, 1850).