A sentencing court commits a material misdirection warranting appellate intervention when it: (1) fails to properly identify and weigh aggravating and mitigating circumstances; (2) overemphasises certain sentencing objectives (such as general deterrence) to the exclusion of others (such as rehabilitation and reformation); and (3) fails to conduct a proper balancing exercise of all relevant factors. Under s 51(3)(a) of the Criminal Law Amendment Act 105 of 1997, 'substantial and compelling circumstances' justifying departure from prescribed minimum sentences can arise from the cumulative effect of multiple mitigating factors, even where no single factor would be sufficient. Such circumstances need not be exceptional or rare. The cumulative mitigating factors in this case (first offender at mature age, financial desperation, lack of premeditation, amateurish execution, no actual weapon, no real danger, full recovery of proceeds, remorse, low risk of recidivism) constituted substantial and compelling circumstances. A sentence, even within prescribed minimums, must remain proportionate to the crime, the criminal and the legitimate interests of society.