Discuss (a) doli incapax

A defence is a legal answer to a prima facie case: facts that, if established, exonerate (an acquittal) or mitigate (a lesser offence or sentence). General (complete) defences are answers available to all or most offences — as opposed to special defences attached to particular crimes (consent in rape's definition; claim of right in theft). The terminology to command: a justification admits the act was right (or tolerated) under the circumstances — the law says "well done," or at least "not wrongful"; an excuse admits the act was wrong but denies the actor's blameworthiness — the law says "wrong, but this actor is not a fit subject of condemnation." The distinction (the unit's organizing axis): justifications negate the act's wrongfulness (the conduct is justified against the world — a third party may even aid the justified actor); excuses negate the actor's culpability (the act remains wrongful; the excuse is personal to this actor in these conditions). Why defences at all? (the rationale list): (i) the capacity principle — punishment presupposes a responsible agent; the child, the person of unsound mind, the coerced lack the capacity criminal censure presupposes; punishing them is cruelty without purpose; (ii) the normative vindication of right — some harm-causing acts are right (the woman who repels her assailant); punishing them would invert the law's message; (iii)…