mental propositions not because of self-evidence, but because of the system of consequences that follows from them, and a practical science like the law ought not to despise that procedure. The abuse of self-evident principles is at the basis of what the Germans call Begriffsjurisprudenz, which Professor Pound calls "mechanical jurisprudence",20 and also of that which is unsatisfactory in the old natural law. The analysis of a few additional examples may perhaps make my point clearer. In discussing creditors' bills in equity, Langdell says: 21 "Indeed, when a debtor dies, his debts would all die with him, did not positive law interpose to keep them alive; for every debt is created by means of an obligation imposed upon the debtor, and it is impossible that an obligation should continue to exist after the obligor had ceased to exist." I have italicized the words "interpose" and "impossible" because these and the later expression that the question is "as old as the law itself" bring into relief the underlying view that the law itself is a logical system in which it is forever impossible for a debt to survive the debtor. But if that were so, how could positive law bring about the impossible? Could positive law change the rules of arithmetic, or make the diagonal and the side of a square commensurate? In point of fact the principle in question is not logically necessary at all. It arose at a time when the creditor could dispose of the actual body and life of the defaulting debtor, hence the relation between debtor and creditor could have been entered only by people who personally trusted each other. If the law of the XII Tables had allowed an assignment of a debt, it would have been socially as serious as if our law allowed an assignment of marital rights. Later on, when the rigor of the old law was softened, the practical reason why the creditor might not be replaced by another person disappeared, and the debtor-creditor relation became depersonalized at one end. The difficulties in the way of depersonalization at the other end were not the logical but the practical ones of harmonizing the security of credit and the maintenance of family continuity on the basis of inheritance. But habits of legal thought in regard to the personal character of the debtor-creditor relation still produce the familiar difficulties of subrogation, etc. 20 Pound, Mechanical Jurisprudence, 8 COL. L. REV. 605, KORKUNOV, THE GENERAL THEORY OF LAW, § 15, and BEKKER, ERNST UND SCHERZ, ch. vii. 21 BRIEF SURVEY OF EQUITY JURISPRUDENCE, p. 126. Another illuminating instance of the confusion between actually existent and logically necessary rules of law is to be found in that most sagacious of the great practical Roman jurists, Papinian. The post-liminium, as is well known, was instituted to the end that citizens might not have their civil rights diminished because of unavoidable absence due to state service. Now, if one, before acquiring title by usus, is captured by the enemy, should possession be restored to him? No, says Ulpian,22 "for possession is for the most part a matter of fact, and matter of fact is not included in the scope of post-liminio." The reasoning here seems conclusive. The law can restore old rights, it cannot restore past states of fact. Reflection, however, shows that while this limitation on the right of post-liminio may have been practically wise, it was by no means logically necessary. An affirmative answer to the question would not have attempted to restore the past but would merely have terminated or wiped out rights acquired by others through the applicant's capture. "Nor ought the applicant," continues Papinian,23 "to be allowed an utilis actio, as it is very unjust to take a thing away from an owner where there was no usus that took it. away; a thing cannot be regarded as lost where it was not taken out of the hands of the party who is said to have lost it." This cannot, however, is not at all convincing when we remember that in the same book it is laid down 24 that "soldiers being quartered in Rome are treated as being absent on state service." Shall we, then, give up all reliance on principles? That would be as wise as giving up the use of our eyes because they are, as a matter of fact, poor optical instruments. Just as a scientific optics aims at correcting our vision through the determination of the natural error of myopia or astigmatism, so a scientific jurisprudence makes such natural principles as "one cannot convey more than in law he has," or "no rights can be acquired by the commission of wrong," more useful by showing their necessary limitations. Closely connected with the use and abuse of first principles is the use of artificial concepts or abstractions in the law. Von Jhering has long ago pointed out 25 that juristic technique is able to reconstruct and simplify the law by a process of analysis similar to the 23 Ibid., IV 6, 20. 24 Ibid., IV, 6, 7. 22 DIGEST IV 6, 19. process whereby, in the course of history, language becomes represented by a more or less phonetic alphabet. The natural unit of language is the sentence, represented in primitive form by pictures. By a process of abstraction we pass from that stage in which thousands of signs are needed to the stage where a few simple phonetic elements suffice to reproduce all the possible combinations of language. Just so, scientific jurisprudence endeavors to analyze all laws as combinations of a few recurrent simple elements. From this point of view, the artificiality of legal concepts is not an objection to their employment. Indeed, there is an advantage in purely artificial symbols. They carry with them only the amount of meaning contained in their definition, without the intellectual and emotional penumbra that more familiar terms always drag with them. The most dangerous concepts of the law are those like direct tax, republican form of government, interstate commerce, restraint of trade, and the like. They seem to be definite in themselves, but when we come to apply them, they prove most illusive. The law, for instance, says, "no taxation except for public purposes.' What are public purposes? The courts have ruled that municipalities may give bounties to grist mills and railroads, but not to factories. Communities may sell gas and electricity, but not coal; may abate a dam for the relief of privately owned meadows, but may not lend money for rebuilding a burnt district.26 The lines of distinction seem quite arbitrary; and when judges try to defend them by such distinctions as that between direct and incidental benefits to the community, a logician cannot help feeling that the decisions may be good but the reasons certainly bad. It is the pernicious fiction that judges never make the law but only declare "the will of the legislator" that makes people blink at the essential indefiniteness of concepts like "due process of law" or "interstate commerce," and pretend to believe that all the constitutional law on these subjects is deduced from the few words of the constitutional enactments. The real work of judicial interpretation is precisely that of making these concepts definite by fixing their limits as questions about them come up. Underlying the logical use of concepts are, of course, the logical 26 Rogers v. Burlington, 3 Wall. (U. S.) 654 (1865). Parkersbury v. Brown, 106 U. S. 487 (1882). Opinion of the Justices, 150 Mass. 592, 24 N. E. 1084 (1890). Lowell v. Boston, 111 Mass. 454 (1873). rules of division, such as the one which demands that subdivisions shall be mutually exclusive. As the law has its excuse for being in the need to regulate future conduct, it must express itself in terms which will exclude the possibility of a case falling in both or neither of two classes which it may set up. Jurists, however, have not paid attention to the difference between logical division and natural classification. The naturalist who studies vertebrates finds that the multitudinous and widely different species may be grouped into fishes, reptiles, etc. If each of these groups has some important trait, the classification will be satisfactory to the naturalist, even though it does not rule out the possibility of species being discovered on the borderland, betwixt and between the groups distinguished. The distinction between plants and animals is a useful one even though there are many species to which either term may be applied. The law oscillates between natural classification and logical division and readily throws the incautious jurist into confusion. In enforcing constitutional provision for "the equal protection of the laws," courts soon realize that an abstract equality, regardless of all differences such as age, sex, occupation, mode of life, etc., would render the law absurd. The courts, then, are forced to recognize the existence of natural classes. But having recognized these natural classes, the prevailing logic of the law compels courts to view them as if they were absolutely logical divisions. The consequent difficulties are amply illustrated in the chapters of Professor Freund's book on the "Police Power." The difficulty of foisting an absolutely logical division upon the facts (or pretending to find them in nature) is illustrated in the usual classification of rights and wrongs. Let us take Langdell's as an illustration. His classification presupposes an absolute distinction between rights and duties. This distinction is not defended. It seems to be based simply on the idea of advantage and disadvantage. May there not be legal relations which can just as well be called rights as duties? Some of the very onerous rights of trustees come very near being of that type. Further Langdell says: 27 "Absolute rights are either personal rights or rights of property. Every personal right is born with the person to whom it belongs, and dies with him. Personal rights, therefore, can neither be acquired nor parted with, and hence they are never the subjects of commerce, 27 Op. cit., 220. nor have they any pecuniary value." But though "we can neither number them nor define them," there is one that is specifically mentioned, viz., “the equal right of all persons to use public highways, navigable waters, and the high seas." Shall we, however, say that an expressman or shipowner cannot sell his right to do business on a given route or river? How does the right to use a navigable river differ from the right to buy and sell liquor or to serve people as an innkeeper? I have no doubt that Langdell's classification of rights and wrongs is useful in helping us to analyze many actual situations, and the difficulties I am raising can probably be met by introducing additional subtle distinctions. But the above considerations indicate that we are not dealing here with an absolutely accurate description. The difference between a useful approximation and an absolutely accurate description is of practical as well as of logical importance. If our classification is only approximate, we must apply it cautiously, expecting some day to come across actual cases which it will not fit, and where practical injustice will result from the attempt to make the facts fit our preconceived account. The various instances of the abuse of legal logic adduced by writers like Von Jhering, Korkunov, Demogue, and Pound, are all cases of an overhasty application of logic to a complex material and do not, of course, show the breakdown of logic itself. Nevertheless, it is fair to add that a great many of the difficulties are due to the inadequacies of the Aristotelian account of logic, which up to recently was the only one in the field. The Aristotelian logic, with its subject-predicate doctrine, is primarily a logic of subsumption and applies best to a system like the biology of which Aristotle was a master, viz., a system of fixed classes. It is only modern logic that can deal adequately with a changing system, since modern logic, like modern mathematics, deals with the invariant rules governing possible transformations. The limitation which underlies the old Aristotelian logic shows itself in the familiar difficulty as to the presence of discretion in the law. The law is primarily directed toward certainty, which, according to the classical view, can be produced only by definite rules that leave no room for individual discretion. Individual discretion, whether of judge or of legislator acting under constitutionally limited powers, appears to this view synonymous with the absence of law. Thus in the criminal law the old maxim is, fix the offense |