F.2d at 1004. Although Congress empowered the federal courts through Rule 501 to ^continue the evolutionary development of testimonial privileges," Trammel 1. United States, 445 U.S. 40, 47, 100 S.Ct. 906, 910, 63 L.Ed.2d 186 (1980), we disfavor newly minted privileges, which ^contravene the fundamental