Legal Question in Constitutional Law in Pennsylvania

Re: Swearing oath to tell the truth...

If you are a party, he court has authority over you on that basis. If you are a third-party witness, the court has power over you because you were subpoenaed or because you showed up to testify on your own. The court's authority over you already exists when you are asked to take the oath.

If a witness has religious grounds for refusing to "swear" to tell the truth, he can instead "affirm" that his testimony will be truthful. If a witness just wants to be uncooperative and refuses to promise his testimony will be truthful, then he can -- and should -- be held in contempt.

The law requires witnesses to tell the truth when they testify at a deposition, before a grand jury or in court. If you plan to play games with this requirement you should be sure to have a toothbrush with you when you get to court, since it will be a while before you return home.