This article refers to a kind of understanding.

For the political tract Common Sense, see Thomas Paine.

For the rapper formerly known as "Common Sense", see Common (rapper).

Common sense, roughly speaking, is what people in common would agree: that which they "sense" in common as their shared natural understanding. Some use the phrase to refer to beliefs or propositions that in their opinion they consider would in most people's experience be prudent and of sound judgment, without dependence upon esoteric knowledge or study or research, but based upon what is believed to be knowledge held by people "in common".

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• Since the world is what it is, it is clear that valid reasoning from sound principles cannot lead to error; but a principle may be so nearly true as to deserve theoretical respect, and yet may lead to practical consequences which we feel to be absurd. There is therefore a justification for common sense in philosophy, but only as showing that our theoretical principles cannot be quite correct so long as their consequences are condemned by an appeal to common sense which we feel to be irresistible. The theorist may retort that common sense is no more infallible than logic. But this retort, though made by Berkeley and Hume, would have been wholly foreign to Locke's intellectual temper.
  • Bertrand Russell, A History of Western Philosophy (1945)

• Nothing astonishes men so much as common sense and plain dealing.
  • Ralph Waldo Emerson, Art (1841)

• On dit quelquefois: "Le sens commun est fort rare."
  • People sometimes say: "Common sense is quite rare."
    • Voltaire, "Common Sense," Dictionnaire philosophique portatif (1765)
    • The better known variant of this quote is "Common sense is not so common," said to be in the Dictionnaire philosophique entry "Self-Love"; but it is not found there.

• Common sense always speaks too late. Common sense is the guy who tells you you ought to have had your brakes relined last week before you smashed a front end this week. Common sense is the Monday morning quarterback who could have won the ball game if he had been on the team. But he never is. He's high up in the stands with a flask on his hip. Common sense is the little man in a grey suit who never makes a mistake in addition. But it's always somebody else's money he's adding up.
  • Philip Marlowe in Playback (1958), by Raymond Chandler

• Le bon sens est la chose du monde la mieux partagée, car chacun pense en être bien pourvu.
  • Translation: "Common sense is the best distributed thing in the world, for we all think we possess a good share of it."
  • René Descartes, Discours de la Méthode (1637)

• Misprize common sense at your peril is my motto.
  • A policeman, in Stanley and the Women by Kingsley Amis

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• It is inaccurate to say I hate everything. I am strongly in favor of common sense, common honesty, and common decency. This makes me forever ineligible for public office.
  • H. L. Mencken

• There are people who are so full of common sense that they haven't the slightest cranny left for their own sense.
  • Miguel de Unamuno

• Common sense is the collection of prejudices acquired by age eighteen.
  • Attributed to Albert Einstein

• Common sense is that which tells us the world is flat.
  • Stuart Chase, quoted in S. I. Hayakawa's Language in Thought and Action

• Common sense is the least common of all senses
  • Attributed to Joel Montes

• Common sense...Get some!
  • Author Unknown