Queen v. Tolson

23 Q.B.D. 185-186 (1889)

Stephen, J.:

 . . . Though this phrase (non est reus, nisi mens sit rea) is in common use, I think it most unfortunate, and not only likely to mislead, but actually misleading, on the following grounds.  It naturally suggests that apart from all particular definitions of crimes, such a thing exists as a “mens rea”, or “guilty mind”, which is always expressly or by implication involved in every definition.  This is obviously not the case, for the mental elements of different crimes differ widely.  “Mens rea” means, in the case of murder, malice aforethought; in the case of theft, an intention to steal; in the case of rape, an intention to have forcible connection with a woman without her consent; and in the case of receiving stolen goods, knowledge that the goods were stolen.  In some cases it denotes mere inattention.  For instance, in the case of manslaughter by negligence it may mean forgetting to notice signal.  It appears confusing to call so many dissimilar states of mind by one name.  It seems contradictory indeed to describe a mere absence of mind as a “mens rea”, or guilty mind.  The expression again is likely to and often does mislead.  To an unlegal mind it suggests that by the law of England no act is a crime which is done from laudable motives, in other words, that immorality is essential to crime.