Brennan held that the rights to be determined in a bankruptcy proceeding were not Congressionally created rights, and therefore the Bankruptcy Act encroached upon the powers of Article III courts. The rights Northern claimed against Marathon were contractual in nature, and as such were creatures of state law. Moreover, the jurisdiction granted to the bankruptcy courts under the Act was too broad, vesting them jurisdiction over all civil proceedings arising under Title 11 and in related cases, and granting them the power to issue final judgments. Thus, while Congress did retain the power to assign certain matters to non-Article III tribunals, this power was limited to rights created by federal statute and the powers of the tribunal had to be narrower than what an Article III court could exercise.