Potter Stewart

“ What thus began as a disqualification of either spouse from testifying at all yielded gradually to the policy of admitting all relevant evidence, until it has now become simply a privilege of the criminal defendant to prevent his spouse from testifying against him. Compare Stein v. Bowman, 13 Pet. 209, 10 L.Ed. 129; Wolfle v. United States, 291 U.S. 7, 14, 54 S.Ct. 279, 280, 78 L.Ed. 617; Funk v. United States, 290 U.S. 371, 54 S.Ct. 212, 78 L.Ed. 369. [2]
Any rule that impedes the discovery of truth in a court of law impedes as well the doing of justice. ”

“ When such a rule is the product of a conceptualism long ago discarded, is universally criticized by scholars, and has been qualified or abandoned in many jurisdictions, it should receive the most careful scrutiny. ”