When it is said that something is left to the discretion of a judge, it signifies that he ought to decide according to the rules of equity, and the nature of circumstances.
The discretion of a judge is said to be the law of tyrants; it is always unknown; it is different in different men; it is casual and depends upon constitution, temper, and passion. In the best, it is oftentimes caprice; in the worst, it is every vice, folly and passion, to which human nature is liable.
There is a species of discretion which is authorized by express law, and, without which, justice cannot be administered; for example, an old offender, a man of much intelligence and cunning, whose talents render him dangerous to the community, induces a young man of weak intellect to commit a larceny in company with himself; they are both liable to be punished for the offence. The law, foreseeing such a case, has provided that the punishment should be proportioned so as to do justice, and it has left such apportionment to the discretion of the judge. It is evident that, without such discretion, justice could not be administered, for one of these parties assuredly deserves a much more severe punishment than the other.
Crim. Law. The ability to know and distinguish between good and evil; between what is lawful and what is unlawful.
The age at which children are said to have discretion, is not very accurately ascertained. Under seven years, it seems that no circumstances of mischievous discretion can be admitted to overthrow the strong presumption of innocence, which is raised by an age so tender. Between the ages of seven and fourteen, the infant is, prima facie, destitute of criminal design, but this presumption diminishes as the age increases, and even during this interval of youth may be repelled by positive evidence of vicious intention; for tenderness of years will not excuse a maturity in crime, the maxim in these cases being, malitia supplet aetatem. At fourteen, children are said to have acquired legal discretion.