Thomas Jefferson on Constitutions + Founders

Some men look at constitutions with sanctimonious reverence, and deem them like the arc of the covenant, too sacred to be touched. They ascribe to the men of the preceding age a wisdom more than human, and suppose what they did to be beyond amendment. I knew that age well; I belonged to it, and labored with it. It deserved well of its country. It was very like the present, but without the experience of the present; and forty years of experience in government is worth a century of book-reading; and this they would say themselves, were they to rise from the dead. I am certainly not an advocate for frequent and untried changes in laws and constitutions. I think moderate imperfections had better be borne with; because, when once known, we accommodate ourselves to them, and find practical means of correcting their ill effects. But I know also, that laws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths disclosed, and manners and opinions change with the change of circumstances, institutions must advance also, and keep pace with the times. We might as well require a man to wear still the coat which fitted him when a boy, as civilized society to remain under the regimen of their barbarous ancestors. It is this preposterous idea which has lately deluged Europe in blood. Their monarchs, instead of wisely yielding to the gradual change of circumstances, of favoring progressive accommodation to progressive improvement, have clung to old abuses, entrenched themselves behind steady habits, and obliged their subjects to seek through blood and violence rash and ruinous innovations, which, had they been referred to the peaceful deliberations and collected wisdom of the nation, would have been put into acceptable and salutary forms. Let us follow no such examples, nor weakly believe that one generation is not as capable as another of taking care of itself, and of ordering its own affairs. 

— Thomas Jefferson, in a letter to Samuel Kercheval Monticello, July 12, 1816, The Letters of Thomas Jefferson: 1743-1826, http://www.let.rug.nl/usa/P/tj3/writings/brf/jefl246.htm