The contradictory experiments of chemists leave us at liberty to conclude what we please. My conclusion is, that art has not yet invented sufficient aids to enable such subtle bodies [air, light, &c.] to make a well-defined impression on organs as blunt as ours; that it is laudable to encourage investigation but to hold back conclusion.

In matters of principle, stand like a rock.

You have not been mistaken in supposing my views and feeling to be in favor of the abolition of war. Of my dispos[i]tion to maintain peace until its condition shall be made less tolerable than that of war itself, the world has had proofs, and more, perhaps, than it has approved. I hope it is practicable, by improving the mind and morals of society, to lessen the dispos[i]tion to war; but of its abolition I despair.

That the several states who formed that instrument, being sovereign and independent, have the unquestionable right to judge of its infraction; and that a nullification, by those sovereignties, of all unauthorized acts done under colour of that instrument, is the rightful remedy.

Man [is] a rational animal, endowed by nature with rights and with an innate sense of justice.

It is in the love of one's family only that heartfelt happiness is known.

Reason and free inquiry are the only effectual agents against error... They are the natural enemies of error, and of error only... If [free enquiry] be restrained now, the present corruptions will be protected, and new ones encouraged.