I believe you are referring to Danforth's speech when he is speaking to Reverend Hale and others. In this speech, Danforth uses the legal term ipso factoin describing witchcraft. This latin phrase means by the fact itself. He also states that witchcraft is an invisible crime; therefore, judging a witch is a direct consequence of witchcraft itself. He sparates withcraft from ordinary crimes because in ordinary crimes you will have other witnesses to help prove the innocence or guilt of a person, but with witchcraft, because the crime is invisible, it is ipso facto. By the fact itself, witchcraft, can only be witnessed by the witch and the victim. Let's not forget that the irony in this statement is that witchcraft is an invisible crime so when Danforth says, "I have been thirty-two year at the bar, sir, and I should be confounded were I called upon to defend these people," he is saying that these people do not need lawyers to defend them because no one can see the crime but the witch and victim. Therefore, judgment on a witch is inevitable and will result from the direct actions of the witch.