A D may commit the AR of an offence with the requisite MR and yet escape liability because he
has a defence.
Defences have been broadly classified into 2 groups (although these classifications are not
water tight):
1. Justification:
a. Focuses on what the defendant did and claims that what he or she did was
what the law permitted him or her to do.
b. Normally this is because society has approved of what the defendant has
done.
2. Excuse:
a. With an excuse the defendant admits that what he or she did was not
permissible, but what they did does not deserve to be blamed.
b. May be due to mental state for example.
Paul Robin stated ‘an actor’s conduct is justified; an actor is excused’.
The different can be traced to George Fletcher, who set out the key differences in
“Rethinking Criminal Law”.
Defences have also been categorised on the basis of their theoretical foundations under the
following headings (again has been subject to criticism):
The Choice Theory:
o View that the defendant should be punished only for what he or she chose to do.
o Under this theory the law should provide a defence to a defendant who did not
choose to act in way he or she did, for example where the defendant is an
automaton.
o H. Hart has suggested, ‘a moral licence to punish is needed by society + unless a
man has the capacity and fait opportunity or chance to adjust his behaviour to
the law, its penalties ought not to be applied to him’.
o An objection to the choice theory is that in making a moral judgement on the
defendant’s actions choice is arguably only one criterion to consider; the
defendant’s attitudes + motives may also be relevant but these are excluded by
this theory.
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