3. Chief Justice Warren’s opinion relied on SIBBACH v. WILSON & CO., 312 U.S. 1, 61 S.Ct. 422, 85 L.Ed. 479 (1941), to define when a rule is procedural for purposes of 28 U.S.C.

§ 2072(a). In Sibbach, plaintiff sued defendant in an Illinois federal district court for damages inflicted in Indiana. The Supreme Court affirmed the District Court’s order that plaintiff undergo a physical examination pursuant to Federal Rule 35, despite an Illinois policy forbidding compulsory physical examinations. The Court concluded that Rule 35 was within the ambit of congressional power, since Rule 35 does not “abridge, enlarge, [or] modify substantive rights, in the guise of regulating procedure.” Moreover, the Court rejected plaintiff’s argument that a rule regulating procedure still could so affect a substantial personal right as to violate the Rules Enabling Act. In an opinion written by Justice Roberts, the Court held:

* * * If we were to adopt the suggested criterion of the importance of the alleged right we should invite endless litigation and confusion * * *. The test must be whether a rule really regulates procedure the judicial process for enforcing rights and duties recognized by substantive law and for justly administering remedy and redress for disregard or infraction of them. That the rules in question are such is admitted.

Id. at 14, 61 S.Ct. at 426, 85 L.Ed. at 485. Justice Frankfurter dissented. He argued that Rule 35, which provides for “the invasion of the person,” is quite different from other rules of procedure. He noted, furthermore, that the Rules are effective automatically absent a veto by Congress, so that “to draw any inference of tacit approval from non-action by Congress is to appeal to unreality.” In his view, therefore, “to make the drastic change that Rule 35 sought to introduce would require explicit legislation.” Id. at 18, 61 S.Ct. at 428 29, 85 L.Ed. at 487.