In this Article, I argue that the spirit of Swift v. Tyson is alive today--and that it's a good thing too. (1) As it is usually understood, Swift depended on a nonpositivist theory of the common law that few currently share). (2) I will argue that Swift was in fact struggling with a question of state law that commonly arises today. This is the question of extra jurisdictional effect--that is, whether state authorities intend their legal rules to be used in other court systems.(3)
Extrajurisdictional effect is puzzling because, absent certification, the courts of the state whose rules are at issue have no occasion to discuss it. They are concerned with the rules they are obligated to follow, because that is what matters to the parties before them. What the courts of other jurisdictions should do is a question that those courts will face. As a result, extrajurisdictional effect is the legal equivalent of dark matter, which can be observed only through its gravitational effect upon other bodies. (4) Unless the question of extrajurisdictional effect is certified to the relevant state's supreme court, the only courts that will discuss it are those not in a position to provide authoritative answers. This gives a misty and jurisprudential aura to what is in fact a straightforward question of state law.
This Article has three Parts. I devote the first to showing that the conception of the general common law expressed in Swift v. Tyson was compatible with legal positivism. In the second, I argue that the heart of the disagreement between advocates of Swift and Erie was a difference of opinion about extrajurisdictional effect: in particular, whether a state's officials wanted the decisions of the state's courts concerning the common law to bind federal and sister state courts when adjudicating events occurring within the state's borders. What made the disagreement so intractable--and what made it appear as if it was a jurisprudential question to be resolved through a priori reasoning--was that it concerned dark matter. The courts of the state whose decisions were at issue never had occasion to settle the question. Had certification been possible, the disagreement could have been quickly resolved.
In the third Part, I argue that the problem of dark matter still arises and produces positions akin to Swift and Erie. One example concerns the law of choice of law. There is currently a debate about whether federal and sister state courts should respect a state's choice-of-law rules. Courts generally take a Swiftian approach to the question. The fact that a state supreme court would not apply the state's law to certain facts does not mean that federal or sister state courts cannot. But a number of scholars have argued that an Erie approach should be used. State supreme court decisions should be treated as authoritative concerning the territorial scope of the state's law.
Here too the debate has proved intractable because it is about dark matter. No state supreme court has ever had occasion to decide whether its choice-of-law rules have extrajurisdictional effect. The absence of authoritative decisions has made the debate appear as if it is a jurisprudential matter to be resolved by a priori reasoning. But a very simple solution has been ignored: certification of the question to the relevant state supreme court. I argue that the consequence of such certification would be a vindication of Swift over Erie.
As it is usually described, Swift v. Tyson depended upon a nonpositivist conception of the common law. (5) To get a clear view of whether this is in fact true, we need some understanding about what legal positivism and its competitors are.
Current philosophers of law generally identify legal positivism by means of two theses. According to the social fact thesis, the law of a jurisdiction is fundamentally a matter of social facts--usually concerning the attitudes and actions of officials within that jurisdiction. …