“Books constitute capital. A library book lasts as long as a house, for hundreds of years. It is not, then, an article of mere consumption but fairly of capital, and often in the case of professional men, setting out in life, it is their only capital.”

“To the corruptions of christianity I am indeed opposed; but not to the genuine precepts of Jesus himself. I am a Christian in the only sense in which he wished any one to be; sincerely attached to his doctrines, in preference to all others; ascribing to himself every human excellence, and believing he never claimed any other.”

“I find that the harder I work, the more luck I seem to have.”

“I would rather be exposed to the inconveniences attending too much liberty, than those attending too small a degree of it.”

“A democracy is nothing more than mob rule, where fifty-one percent of the people may take away the rights of the other forty-nine.” 

“The will of the people is the only legitimate foundation of any government, and to protect its free expression should be our first object.” 

“I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccesful rebellions indeed generally establish the incroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions, as not to discourage them too much. It is a medecine necessary for the sound health of government.”

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

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

“If by religion we are to understand sectarian dogmas, in which no two of them agree, then your exclamation on that hypothesis is just, "that this would be the best of worlds if there were no religion in it.” 

“Leave no authority existing not responsible to the people.”

“...never [enter] into dispute or argument with another. I never saw an instance of one of two disputants convincing the other by argument. I have seen many, on their getting warm, becoming rude, & shooting one another. ... When I hear another express an opinion which is not mine, I say to myself, he has a right to his opinion, as I to mine; why should I question it? His error does me no injury, and shall I become a Don Quixote, to bring all men by force of argument to one opinion? ... There are two classes of disputants most frequently to be met with among us. The first is of young students, just entered the threshold of science, with a first view of its outlines, not yet filled up with the details & modifications which a further progress would bring to their knoledge. The other consists of the ill-tempered & rude men in society, who have taken up a passion for politics. ... Consider yourself, when with them, as among the patients of Bedlam, needing medical more than moral counsel. Be a listener only, keep within yourself, and endeavor to establish with yourself the habit of silence, especially on politics. In the fevered state of our country, no good can ever result from any attempt to set one of these fiery zealots to rights, either in fact or principle. They are determined as to the facts they will believe, and the opinions on which they will act. Get by them, therefore, as you would by an angry bull; it is not for a man of sense to dispute the road with such an animal.”

“With your talents and industry, with science, and that steadfast honesty, which eternally pursues right, regardless of consequences, you may promise yourself everything but health, without which there is no happiness.”

“God grant that men of principle shall be our principal men.”

“Our Revolution commenced on more favorable ground. It presented us an album on which we were free to write what we pleased. We had no occasion to search into musty records, to hunt up royal parchments, or to investigate the laws and institutions of a semi-barbarous ancestry. We appealed to those of nature, and found them engraved on our hearts. Yet we did not avail ourselves of all the advantages of our position. We had never been permitted to exercise self-government. When forced to assume it, we were novices in its science. Its principles and forms had entered little into our former education. We established however some, although not all its important principles. The constitutions of most of our States assert, that all power is inherent in the people; that they may exercise it by themselves, in all cases to which they think themselves competent, (as in electing their functionaries executive and legislative, and deciding by a jury of themselves, in all judiciary cases in which any fact is involved,) or they may act by representatives, freely and equally chosen; that it is their right and duty to be at all times armed; that they are entitled to freedom of person, freedom of religion, freedom of property, and freedom of the press.”