^"common sense." Merriam-Webster Online Dictionary: "sound and prudent judgment based on a simple perception of the situation or facts."
"common sense." Cambridge Dictionary: "the basic level of practical knowledge and judgment that we all need to help us live in a reasonable and safe way."
van Holthoorn & Olson (1987): "common sense consists of knowledge, judgement, and taste which is more or less universal and which is held more or less without reflection or argument."
C.S. Lewis (1967) wrote that what common sense "often means" is "the elementary mental outfit of the normal man."
^The Shorter Oxford English Dictionary of 1973 gives four meanings of "common sense": An archaic meaning is "An internal sense which was regarded as the common bond or centre of the five senses"; "Ordinary, normal, or average understanding" without which a man would be "foolish or insane", "the general sense of mankind, or of a community" (two sub-meanings of this are good sound practical sense and general sagacity); A philosophical meaning, the "faculty of primary truths."