Intoxication and mistake

Intoxication and mistake are two of the most doctrinally contested topics in English criminal law. Both involve the defendant''s state of mind: intoxication asks whether voluntary impairment can negate mens rea; mistake asks whether a defendant''s incorrect belief can do so. The doctrines have been shaped by competing concerns about (i) personal responsibility for self-induced incapacity, (ii) the moral significance of mistaken belief, and (iii) the practical consequences of broad defences for public safety.

The modern law on intoxication is governed by DPP v Majewski [1977] AC 443: voluntary intoxication is a defence to crimes of specific intent but not to crimes of basic intent. The specific/basic intent distinction has been criticised but remains the doctrinal anchor. The law on mistake is governed by DPP v Morgan [1976] AC 182 (subjective standard for mens rea) and the Beckford / Williams (Gladstone) line on mistake-based defences.

This week traces the doctrinal architecture, the principal cases, the contemporary academic debates (the Law Commission''s 2009 report on intoxication; the post-Caldwell/G simplification of mens rea), and the comparative material. The topic connects to W2 (mens rea), W4 (voluntary manslaughter), and W11 (defences — duress, necessity, self-defence).

The historical position on intoxication was a categorical bar: drunkenness was no defence (R v Pearson (1835) 2 Lewin 144 — Park J: ''voluntary drunkenness furnishes no excuse for crime''). The position softened in the nineteenth century to allow intoxication to negate specific elements of mens rea (DPP v Beard [1920] AC 479: intoxication could reduce murder to manslaughter by negating intent). DPP v Majewski [1977] AC 443 produced the modern compromise: intoxication is a defence to specific-intent crimes but not to basic-intent crimes.

Mistake was governed by the Tolson rule (R v Tolson (1889) 23 QBD 168 — mistake must be reasonable) until DPP v Morgan [1976] AC 182 introduced the subjective standard: a mistake need not be reasonable as long as it was honestly held. The post-Morgan trajectory has been mixed: subjective for mens rea (B (A Minor) v DPP [2000] 2 AC 428) but objective elements have been preserved for some defences (statutory rape; sexual offences post-Sexual Offences Act 2003).

(1) Voluntary intoxication and the Majewski rule. DPP v Majewski: voluntary intoxication is a defence to crimes of specific intent (where the prosecution must prove a particular further intention beyond the basic actus reus — eg s 18 OAPA wounding with intent; murder; theft) but not to crimes of basic intent (where recklessness or general intention suffices — eg s 47 OAPA assault occasioning ABH; s 20 OAPA malicious wounding; manslaughter). The rule produces the result that voluntary intoxication can reduce murder to manslaughter (Beard) but cannot acquit altogether of basic-intent offences.

Five graded practice questions in the panel below — two foundation on Majewski and Morgan, two standard on Heard and Kingston, one challenge on the Law Commission reform proposal.

See the Further Reading panel for Ashworth, Horder, Smith and Hogan, the Law Commission Report 2009, and the post-G doctrinal commentary.