Solution

R V. Prince (1683) 2 CHC 154 - laid down some rules to determine the question of justification of offence either due to mistake of fact or law : 1) when act by itself is plainly criminal , but is more severely punishable if certain circumstances exist , then ignorance of those circumstances is no answer to a charge for the aggravated offence. 2) If , however , an act is prima facie innocent , but is an offence if certain circumstances exist , then ignorance of those circumstances is a good defence to the charge. 3)If the act itself is wrong , and becomes criminal under certain circumstances , the person who commits such wrongful act cannot argue he was ignorance of facts which turned wrong into crime. 4)The state of the defendants mind must amount to absolute ignorance of the existence of the circumstances which alter the character of the Act, or to belief in its non-existence. R v Dudley and Stephens (1884) 14 QBD 273, DC is a leading English criminal case which established a precedent throughout the common law world that necessity is not a defence to a charge of murder. Rex. v. Bourne: There was no change in the legislation per se, but it was held that doctor must have the discretion to take the necessary steps if the life of the patient is in jeopardy, Justice Mcnaughten believed that some legalized abortion was required. Bourne was released and the medical community lauded his actions