Common sense is the measure of the possible; it is composed of experience and prevision; it is calculation applied to life. (26 Dec 1852)

Common sense … has the very curious property of being more correct retrospectively than prospectively. It seems to me that one of the principal criteria to be applied to successful science is that its results are almost always obvious retrospectively; unfortunately, they seldom are prospectively. Common sense provides a kind of ultimate validation after science has completed its work; it seldom anticipates what science is going to discover.

Do not imagine that mathematics is harsh and crabbed, and repulsive to common sense. It is merely the etherealisation of common sense.

Gods are fragile things they may be killed by a whiff of science or a dose of common sense.

Good-sense, which only is the gift of Heaven,
And though no science, fairly worth the seven.

In its famous paradox, the equation of money and excrement, psychoanalysis becomes the first science to state what common sense and the poets have long known—that the essence of money is in its absolute worthlessness.

It is impossible for us, who live in the latter ages of the world, to make observations in criticism, morality, or in any art or science, which have not been touched upon by others. We have little else left us but to represent the common sense of mankind in more strong, more beautiful, or more uncommon lights.

It would be foolish to give credit to Euclid for pangeometrical conceptions; the idea of geometry deifferent from the common-sense one never occurred to his mind. Yet, when he stated the fifth postulate, he stood at the parting of the ways. His subconscious prescience is astounding. There is nothing comperable to it in the whole history of science.

John Locke invented common sense, and only Englishmen have had it ever since!

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, I believe, nothing but trained and organised common-sense, differing from the latter only as a veteran may differ from a raw recruit; and its methods differ from those of common-sense only so far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.

Science when well-digested is nothing but good sense and reason.

Someday someone will write a pathology of experimental physics and bring to light all those swindles which subvert our reason, beguile our judgement and, what is worse, stand in the way of any practical progress. The phenomena must be freed once and for all from their grim torture chamber of empiricism, mechanism, and dogmatism; they must be brought before the jury of man's common sense.

The history of science is the saga of nature defying common sense.

The theory of probabilities is basically only common sense reduced to a calculus. It makes one estimate accurately what right-minded people feel by a sort of instinct, often without being able to give a reason for it.

There is nobody so irritating as somebody with less intelligence and more sense than we have.

What the founders of modern science, among them Galileo, had to do, was not to criticize and to combat certain faulty theories, and to correct or to replace them by better ones. They had to do something quite different. They had to destroy one world and to replace it by another. They had to reshape the framework of our intellect itself, to restate and to reform its concepts, to evolve a new approach to Being, a new concept of knowledge, a new concept of science—and even to replace a pretty natural approach, that of common sense, by another which is not natural at all.