But although such tools have worked under certain circumstances, most can be fooled with enough preparation, and none are considered reliable enough to even be admissible in court.
He offered to move a few more detainees but ducked a hard question: what to do with those thought too dangerous to release, but who cannot be prosecuted for lack of admissible evidence.
Socrates' point is that whereas narration is admissible in the just city, some mimesis should not be admitted because the guardians might seek to imitate bad characters and become bad themselves.