Common sense is "knowledge, judgement, and taste which is more or less universal and which is held more or less without reflection or argument". As such, it is often considered to represent the basic level of sound practical judgement or knowledge of basic facts that any adult human being ought to possess. It is "common" in the sense of being shared by nearly all people. Relevant terms from other languages used in such discussions include the aforementioned Latin, itself translating Ancient Greek κοινὴ αἴσθησις, and French bon sens. However, these are not straightforward translations in all contexts, and in English different shades of meaning have developed. In philosophical and scientific contexts, since the Age of Enlightenment the term "common sense" has been used for rhetorical effect both approvingly and disapprovingly. On the one hand it has been a standard for good taste, good sense, and source of scientific and logical axioms. On the other hand it has been equated to conventional wisdom, vulgar prejudice, and superstition.
"Common sense" has at least two older and more specialized meanings which have influenced the modern meanings, and are still important in philosophy. The original historical meaning is the capability of the animal soul, 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. The 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 the philosophical meanings 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 in turn become international.
