It’s developed in judicial decisions
Basdekis 96, Professor of Psychology, Georgetown University. (Athanasios, June 1996, Book Note: Perfection by Nullification Commonsense Justice: Jurors' Notions of the Law. By Norman J. Finkel. Cambridge and London: Harvard University Press, 1995. Pp. 390. $ 39.95., 105 Yale L.J. 2285, 2286. Lexis accessed online via KU libraries)
Finkel structures Commonsense Justice around one question: "Should the law follow the path laid by community sentiment, or should the community follow the path the law has laid?" (p. 1). He believes that the "law on the books" - as set down in the Constitution and statutes and developed through judicial decisions - must yield to another law: commonsense justice. The latter concept reflects the "intuitive notions [of fairness and justice that] jurors bring with them to the jury box" (p. 2). Commonsense notions "are at once legal, moral, and psychological" (p. 2).