- General defence
- Burden of proof is on the defence and has to be proved on the BALANCE OF PROBABILITIES
- The rules of insanity come under the case of M'NAGHTEN saying in order to claim insanity one must:
- Have a defect of reason
- Have a disease of the mind
- Not know the nature or quality of his acts
DEFECT OF REASON
The defect of reason rule means that the defendant must have his ability to reason impaired; if he has the ability to reason but fails to then this is no a defect of reason. Mere absent mindedness or confusion is not defect of reason, that was shown in the case of CLARKE
DISEASE OF THE MIND
The disease of the mind is an illness that affects your mind and this can be a mental or physical illness... AS LONG AS IT AFFECTS THE MIND. An example of a physical illness that affects the mind is arteriosclerosis and this was shown in Kemp.
The disease of the mind can be 'organic' so it can derive from a problem with organs that affects the mind: HENNESSY.
NOT KNOWING THE NATURE OR QUALITY..
Finally, the defedant must not know the nature or qualities of his acts.This may be because:
- The defendant's consciousness is impaired or they are unconscious
- The mental illness causes them to not know what they are doing is WRONG.
In the cases of Kemp, Sullivan and Hennessy, the defendants did not know what they were doing so they COULD CLAIM INSANITY
If the defendant does have a mental illness but can distinguish between the legal means of right and wrong then this is not going to go under insanity- WINDLE
If the defedant DOES NOT KNOW WHAT HE DID WAS LEGALLY WRONG... THEN INSANITY CAN BE CLAIMED