The interesting and, we hold, controlling issue in this appeal is the extent to which "substantiality" of the federal issue presented permits a federal court to bypass that issue and to proceed to a resolution on the merits of the controversy solely on the basis of state law. We hold that a determination that the federal issue presented is substantial is a jurisdictional requirement which must be met before the district court can address the state issue. Decisions of the Supreme Court such as Hagans v. Lavine, 415 U.S. 528, 39 L. Ed. 2d 577, 94 S. Ct. 1372 (1974), Schmidt v. Oakland Unified School District, 457 U.S. 594, 73 L. Ed. 2d 245, 102 S. Ct. 2612 (1982) (per curiam), and Siler v. Louisville & Nashville R. Co., 213 U.S. 175, 53 L. Ed. 753, 29 S. Ct. 451 (1909), and decisions of our court in cases such as Seals v. Quarterly County Court, 562 F.2d 390 (6th Cir. 1977), are fully supportive of this position and do not even suggest a contrary result.