In criminal law, Blackstone's formulation (also known as Blackstone's ratio or the Blackstone ratio) is the principle that it is "better that ten guilty persons escape than that one innocent suffer". Criminal law (also known as penal law) is the body of common law that punishes criminals for committing offences against the state. ...

Named after the English jurist William Blackstone, the principle expressed in the formulation is much older, being closely tied to the presumption of innocence in criminal trials. The first expression of the formulation is found in Sir John Fortescue's De Laudibus Legum Angliae (c. 1470), where he states that "one would much rather that twenty guilty persons should escape the punishment of death, than that one innocent person should be condemned, and suffer capitally." Similarly, on October 3, 1692, while decrying the Salem witch trials, Increase Mather adapted Fortescue's statement and wrote, "It were better that Ten Suspected Witches should escape, than that the Innocent Person should be Condemned." Sir William Blackstone, (July 10, 1723 – February 14, 1780) was an English jurist and professor who produced the historical treatise on the common law called Commentaries on the Laws of England, first published in four volumes over 1765–1769. ... Presumption of innocence is a legal right that the accused enjoys in criminal trials in many modern nations. ... Sir John Fortescue (c. ... 1876 illustration of the courtroom; the central figure is usually identified as Mary Walcott The Salem witch trials, which began in 1692 (also known as the Salem witch hunt and the Salem witchcraft episode), resulted in a number of convictions and executions for witchcraft in both Salem Village and Salem... Increase Mather, 1688, by John van der Spriett Increase Mather (June 21, 1639 – August 23, 1723) was a Puritan educator and clergyman, noted for being the father of Cotton Mather. ...

The ratio itself - 10 guilty to 1 innocent in Blackstone's archetypal formulation and 20:1 in Fortescue's original formula - is the subject of much variance among commentators, with utilitarianist opinions inclining towards lower ratios (Bismarck stated "it is better that ten innocent men suffer than one guilty man escape"). Bismarck redirects here. ...

External links

• n Guilty Men, Alexander Volokh