“If you want something you've never had You must be willing to do something you've never done.” 

“I think one travels more usefully when they travel alone, because they reflect more."

“In every country and in every age, the priest has been hostile to liberty. He is always in alliance with the despot, abetting his abuses in return for protection to his own.”

“When the subject is strong, simplicity is the only way to treat it.” 

“The whole art of government consists in the art of being honest. Only aim to do your duty, and mankind will give you credit where you fail.”

“There is a ripeness of time for death,  regarding others as well as ourselves, when it is reasonable we should drop off, and make room for  another growth. When we have lived our generation out, we should not wish to encroach on another.”

“I hope we shall ... crush in it’s birth the aristocracy of our monied corporations which dare already to challenge our government to a trial of strength, and to bid defiance to the laws of their country.”

“Be polite to all, but intimate with few.”

“I consider him [Alexander von Humboldt] the most important scientist whom I have met.”

“Nothing gives one person so much advantage over another as to remain always cool and unruffled under all circumstances.”

“Some men look at constitutions with sanctimonious reverence, and deem them like the ark 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 ever under the regimen of their barbarous ancestors.” 

“The Constitution of most of our states (and of the United States) assert that all power is inherent in the people; that they may exercise it by themselves; that it is their right and duty to be at all times armed.”

“Cultivators of the earth are the most valuable citizens. They are the most vigorous, the most independent, the most virtuous, and they are tied to their country and wedded to its liberty and interests by the most lasting bonds.”

“The contest is not between Us and Them, but between Good and Evil, and if those who would fight Evil adopt the ways of Evil, Evil wins.”

“All tyranny needs to gain a foothold is for people of good conscience to remain silent.”