5 current social norms boni mores objective

5. CURRENT SOCIAL NORMS – BONI MORES
Objective reasonableness is considered as the criterion for the existence of
unlawfulness and the content of what is reasonable, is determined by current
social norms.
According to Van der Merwe and Olivier this criterion is totally objective.
TAKE THE FOLLOWING FOR EXAMPLE:
When Albert holds Benny at gunpoint with a water pistol and demands money and
when Benny shoots Albert with his 9mm parabellum because he thought that the
water pistol was an actual weapon, then Benny's conduct is unlawful. From an
objective point of view, Benny grossly exceeded the limits of self-defence. The fact
that Benny bona fide thought that he was acting lawfully, in self-defence, is
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considered when the question is raised concerning intent and specifically knowledge
of unlawfulness.
The contrary is also true with the totally objective test. When Amy kills Billy with his
gun on Bloemfontein station out of pure callousness and it thereafter transpires that
Billy as it happens, was a terrorist who was about to blow up the station, then Amy's
conduct, from the objective point of view, was not unlawful. The fact that Amy had a
bad motive and did not intend to save lives at the Bloemfontein station does not
detract from the fact that there was no unlawful murder. It will be clear from other
modules that Amy should be found guilty of attempted murder.
The test for unlawfulness, although also objective, differs from the reasonable
man test for negligence.
The difference is clear from the following example:
Professor Alknow, a scientist, works in his laboratory. His son, Boysie approaches
him and says that he is thirsty. Professor Alknow goes to the refrigerator in the
laboratory, looks through bottles and flasks and finds a liquid in a milk bottle which
resembles milk. He pours a glass of this liquid for Boysie, Boysie dies because it was
later found that "the milk" was poison which was stored in the milk bottle. Professor
Alknow's conduct was unlawful (a person may not kill a child by poisoning him) as
well as negligent (the reasonable man would not accept that a milk bottle in a
refrigerator in the laboratory always contains milk).
Suppose Professor Alknow was not working in a laboratory, but in his own kitchen,
Boysie asks him for some milk and Professor Alknow goes to the refrigerator, takes
out the milk bottle and pours a glass of milk for Boysie. Boysie dies because it was
later found that Professor Alknow's wife had mixed an odourless ant poison in the
milk bottle and that she had stored it for a while in the refrigerator out of Boysie's
reach. Professor Alknow's conduct giving poison to Boysie - is still unlawful but not
necessarily negligent. The reasonable man would also under these circumstances
have mistaken the poison for milk.