How Much Should Philosophy Rely on Counter-Examples? The method of counter-examples was introduced to philosophy by that under-achieving gadfly, Socrates, and it was one of Plato’s great achievements that he transcribed some of the conversations in which Socrates used this method.
Justice is not the repayment of what you owe, Socrates argued, because it is not an exercise of justice when you return a weapon that you owe to a homicidal maniac. That example, in the Republic, showed a plausible theory false, but this was not the only use to which Socrates put counter-examples.