A mind that is stretched by a new idea can never go back to its original dimensions.

A patent is property carried to the highest degree of abstraction—a right in rem to exclude, without a physical object or content.

Go on, fair Science; soon to thee
Shall Nature yield her idle boast;
Her vulgar lingers formed a tree,
But thou hast trained it to a post.

Heads I win, tails you lose.

I was just going to say, when I was interrupted, that one of the many ways of classifying minds is under the heads of arithmetical and algebraical intellects. All economical and practical wisdom is an extension or variation of the following arithmetical formula: 2+2=4. Every philosophical proposition has the more general character of the expression a+b=c. We are mere operatives, empirics, and egotists, until we learn to think in letters instead of figures.

I would never use a long word, even, where a short one would answer the purpose. I know there are professors in this country who 'ligate' arteries. Other surgeons only tie them, and it stops the bleeding just as well.

It is better for all the world, if instead of waiting to execute degenerate offspring for crime, or to let them starve for their imbecility, society can prevent those who are manifestly unfit for continuing their kind. The principle that sustains compulsory vaccinations is broad enough to cover cutting Fallopian tubes. Three generations of imbeciles are enough.
[Chief Justice Holmes contributed this opinion to the judgment by which the sterilization law of Virginia was declared constitutional.]

Knowledge—it excites prejudices to call it science—is advancing as irresistibly, as majestically, as remorselessly as the ocean moves in upon the shore.

Science ... in other words, knowledge—is not the enemy of religion; for, if so, then religion would mean ignorance. But it is often the antagonist of school-divinity.

Science is a first-rate piece of furniture for a man's upper chamber, if he has common sense on the ground floor. But if a man hasn't got plenty of good common sense, the more science he has the worse for his patient.

Science is the topography of ignorance. From a few elevated points we triangulate vast spaces, inclosing infinite unknown details. We cast the lead, and draw up a little sand from abysses we may never reach with our dredges.

Throw out opium, which the Creator himself seems to prescribe, for we often see the scarlet poppy growing in the cornfields, as if it were foreseen that wherever there is hunger to be fed there must also be a pain to be soothed; throw out a few specifics which our art did not discover, and it is hardly needed to apply; throw out wine, which is a food, and the vapors which produce the miracle of anaesthesia, and I firmly believe that if the whole materia medica [medical drugs], as now used, could be sunk to the bottom of the sea, it would be all the better for mankind,—and all the worse for the fishes.

We can make an exception of opium 'which the creator seems to prescribe, as we often see the scarlet poppy growing in the corn fields' but all other receipts of Omniscience must be condemned. The purple fox-glove, the many-tinted veratrum the lilac stramonium they are all 'noxious' but a little opium it helps the imagination.
Criticizing the medical use of noxious psychoactive drugs.