Common sense

Common sense is sound, practical judgement concerning everyday matters, or a basic ability to perceive, understand, and judge in a manner that is shared by (i.e., "common to") nearly all people.

The everyday understanding of common sense is ultimately derived from historical philosophical discussions. Relevant terms from other languages used in such discussions include Latin sensus communis, Greek αἴσθησις κοινὴ (aísthēsis koinḕ), and French bon sens, but these are not straightforward translations in all contexts. Similarly in English, there are different shades of meaning, implying more or less education and wisdom: "good sense" is sometimes seen as equivalent to "common sense", and sometimes not.

"Common sense" has at least two specific philosophical meanings. One is as a capability of the animal soul (ψῡχή, psūkhḗ) proposed by Aristotle to explain how the different senses join and enable discrimination of particular objects by people and other animals. This common sense is distinct from the several sensory perceptions and from human rational thought, but it cooperates with both.

A second philosophical use of the term is Roman-influenced and is used for the natural human sensitivity for other humans and the community. Just like the everyday meaning, both of these refer to a type of basic awareness and ability to judge that most people are expected to share naturally, even if they cannot explain why. All these meanings of "common sense", including the everyday ones, are interconnected in a complex history and have evolved during important political and philosophical debates in modern Western civilisation, notably concerning science, politics and economics. The interplay between the meanings has come to be particularly notable in English, as opposed to other western European languages, and the English term has become international.

Since the Age of Enlightenment the term "common sense" has been used for rhetorical effect both approvingly, as a standard for good taste and source of scientific and logical axioms, and disapprovingly, as equivalent to vulgar prejudice and superstition. It was at the beginning of the 18th century that this old philosophical term first acquired its modern English meaning: "Those plain, self-evident truths or conventional wisdom that one needed no sophistication to grasp and no proof to accept precisely because they accorded so well with the basic (common sense) intellectual capacities and experiences of the whole social body." This began with Descartes's criticism of it, and what came to be known as the dispute between "rationalism" and "empiricism". In the opening line of one of his most famous books, Discourse on Method, Descartes established the most common modern meaning, and its controversies, when he stated that everyone has a similar and sufficient amount of common sense (bon sens), but it is rarely used well. Therefore, a skeptical logical method described by Descartes needs to be followed and common sense should not be overly relied upon. In the ensuing 18th century Enlightenment, common sense came to be seen more positively as the basis for modern thinking. It was contrasted to metaphysics, which was, like Cartesianism, associated with the Ancien Régime. Thomas Paine's polemical pamphlet Common Sense (1776) has been described as the most influential political pamphlet of the 18th century, affecting both the American and French revolutions. Today, the concept of common sense, and how it should best be used, remains linked to many of the most perennial topics in epistemology and ethics, with special focus often directed at the philosophy of the modern social sciences.