Swift v. Tyson (1842) 41 U.S. 1, established the principle that if this court took a different view of what the law was in certain classes of cases which ought to be governed by the general principles of commercial law, from the state court, it was not bound to follow the latter. There is, therefore, a large field of jurisprudence left in which the question of how far the decisions of state courts constitute the law of those States is an embarrassing one. The Supreme Court held that certain categories of state judicial decisions were not "laws" for purposes of the Rules of Decisions Act and hence were not binding in federal courts; even under Swift, state statutes unambiguously constituted "laws." The Supreme Court considering a section of the Judiciary Act of 1789, 34, 1 Stat. 92, which stated, in part: "The laws of the several states, except where the constitution, treaties, or statutes of the United States shall otherwise require or provide, shall be regarded as rules of decision in trials at common law in the courts of the United States in cases where they apply." The Court, in explaining its doubt that court decisions constituted "laws" observed: "They are, at most, only evidence of what the laws are, and not of themselves laws. They are often re-examined, reversed, and qualified by the Courts themselves, whenever they are found to be either defective, or ill-founded, or otherwise incorrect.. The Supreme Court, speaking by Mr. Justice Story, said that it entertained no doubt "that a bona fide holder for a pre-existing debt of a negotiable instrument is not affected by any equities between antecedent parties, when he has received the same before it became due, without notice of any such equities." Since the decision in Swift v. Tyson, it has been the accepted doctrine of this court that, in respect of the doctrines of commercial law and general jurisprudence, the courts of the United States will exercise their own independent judgment, and, in respect to such doctrines, will not be controlled by decisions based upon local statutes or local usage, although, if the question is balanced with doubt, the courts of the United States, for the sake of harmony, `will lean to an agreement of views with the state courts. In Swift v. Tyson it seems to have been declared that United States judges were bound to hear and decide a controversy between citizens of different states upon an independent examination of the source of the state law applicable to the controversy in question, and to declare or make the state law by the light of their own intelligence, and not to declare or make it by way of an automatic echo as the state judges may have declared or made it.