Malum in se

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malum in se

(mal-uhm in say) adv. Latin referring to an act that is "wrong in itself," in its very nature being illegal because it violates the natural, moral or public principles of a civilized society. In criminal law it is one of the collection of crimes which are traditional and not just created by statute, which are "malum prohibitum." Example: murder, rape, burglary, and robbery are malum in se, while violations of the Securities and Exchange Act or most "white collar crimes" are malum prohibitum. (See: malum prohibitum)

MALUM IN SE. Evil in itself.
     2. An offence malum in se is one which is naturally evil, as murder, theft, and the like; offences at common law are generally mala in sese.
     3. An offence malum prohibitum, on the contrary, is not naturally an evil, but becomes so in consequence of its being forbidden; as playing at games, which being innocent before, have become unlawful in consequence of being forbidden. Vide Bac. Ab. Assumpsit, A, note; 2 Rolle's Ab. 355.

References in periodicals archive ?
As a statement of black letter law, the rule that ignorance of law excuses malum prohibitum -- but not malum in se -- crimes is overbroad; indeed, it takes no real detective work to find cases that say just the opposite -- that ignorance of law is no excuse "whether the crime charged is malum Prohibitum or malum in se"(90) -- although that proposition too is (as I've just shown) wildly overstated.
96) Life is much easier for a court in these and like cases when it can simply invoke a rule -- "ignorance of the law is never an excuse, for malum prohibitum offenses or malum in se ones" -- that spares it the burden of justifying the denial of a defense.
For one can determine whether a particular species of conduct -- whether possessing a gun, distributing a drug, or neglecting to pay a tax -- is malum in se or malum prohibitum only by appraising that conduct in light of moral norms external to positive law.