When I want to think about what would be the right thing to do, the fair thing to do, the wise thing to do, I can just think of my grandmother. I can always hear her say, "Now sister, you know what's right. Just do right!"
One should follow a man of wisdom who rebukes one for one's faults, as one would follow a guide to some buried treasure. To one who follows such a wise man, it will be an advantage and not a disadvantage.
So in this case, Kalamas, don't go by reports, by legends, by traditions, by scripture, by logical conjecture, by inference, by analogies, by agreement through pondering views, by probability, or by the thought, 'This contemplative is our teacher.' When you know for yourselves that, 'These qualities are unskillful; these qualities are blameworthy; these qualities are criticized by the wise; these qualities, when adopted & carried out, lead to harm & to suffering' - then you should abandon them.
Plato says that the punishment which the wise suffer who refuse to take part in the government, is, to live under the government of worse men; and the like regret is suggested to all the auditors, as the penalty of abstaining to speak,--that they shall hear worse orators than themselves.
Believe nothing just because a so-called wise person said it. Believe nothing just because a belief is generally held. Believe nothing just because it is said in ancient books. Believe nothing just because it is said to be of divine origin. Believe nothing just because someone else believes it. Believe only what you yourself test and judge to be true.