2,194 Quotes by Thomas Jefferson

While the art of printing is left to us science can never be retrograde; what is once acquired of real knowledge can never be lost.

Reason and free inquiry are the only effectual agents against error.

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

I have given up newspapers in exchange for Tacitus and Thucydides, for Newton and Euclid; and I find myself much the happier.

Speaking one day to Monsieur de Buffon, on the present ardor of chemical inquiry, he affected to consider chemistry but as cookery, and to place the toils of the laboratory on the footing with those of the kitchen. I think it, on the contrary, among the most useful of sciences, and big with future discoveries for the utility and safety of the human race.

I [am] obliged to recur ultimately to my habitual anodyne, "I feel: therefore I exist." I feel bodies which are not myself: there are other existencies then. I call them "matter". I feel them changing place. This gives me "motion". Where there is an absence of matter, I call it "void", or "nothing", or "immaterial space". On the basis of sensation, of matter and motion, we may erect the fabric of all the certainties we can have or need.

The attempt of Lavoisier to reform chemical nomenclature is premature. One single experiment may destroy the whole filiation of his terms; and his string of sulphates, sulphites, and sulphures, may have served no end than to have retarded the progress of science by a jargon, from the confusion of which time will be requisite to extricate us.

The more ignorant we become the less value we set on science, and the less inclination we shall have to seek it.

[n regard to Jesus believing himself inspired]This belief carried no more personal imputation than the belief of Socrates that he was under the care and admonition of a guardian demon. And how many of our wisest men still believe in the reality of these inspirations while perfectly sane on all other subjects (Works, Vol. iv, p. 327).