This section is from the book "Science Of Legal Method", by Ernest Bruncken. Also available from Amazon: Science of Legal Method.
The reason or "ratio" of the law is the keystone of the theory of interpretation as elaborated for private law. The distinction drawn between two methods of interpretation and the differences between the results obtained accordingly naturally provoked the question what justification there was for either method and according to what rule one or the other was to be adopted. Obviously, in favor of the grammatical method there is the text itself. But how can one justify a deviation from the sense obtained according to the ordinary rules of the language? Still more, by what right are cases not provided for by the text decided by analogy? The customary answer to these questions reads, the justification lies in the "ratio" of the law; and this conception has to be worked out elaborately in order to cover the question of analogy. The conception of "ratio legis" is a very comprehensive one, and the practice of construing by analogy is founded on but a part of it. In theory, it is customary to set certain limits to the applicability of this doctrine of "ratio legis," but in practice lawyers recognize almost no bounds to its employment in justifying the application of the "logical" method of interpretation. Every time anybody wishes to deviate from the letter of the statute he calls in the "ratio legis" to justify him. The conception of "ratio legis" may therefore be considered as correlative with that of "logical" interpretation,58 subject however to certain reservations. The notion of "ratio legis" is consequently quite as vague and indefinite as that of "logical interpretation." . . . The traditional theory of legislation itself distinguishes several different meanings attaching to the term "reason of the law." Especially, a distinction is drawn between the external circumstances causing the making of the rule ("occasio legis") - a distinction borrowed from the historical sciences, - and a more profound reason for its existence, which one may call the legislative and political reason, or the "ratio legis" in the narrow sense. As the distinction between occasion and cause is used in the historical sciences, which aim at describing empirical reality,59 it is exhaustive, covering the whole series of happenings constituting the cause of a given event. All such happenings are either cause or occasion, there is no third possibility. In fact, as long as one adheres strictly to actual events, no third possibility can well be conceived. The teleological character of legal science, notwithstanding the claims made that it deals merely with things as they positively are, appears clearly from the fact that lawyers recognize a third species of "ratio legis," and moreover lay especial emphasis on this third species while the other two are considered of secondary importance. It is this third species that must explain and support the use of analogy for construction. There is a consensus of opinion that the occasion of the law, as well as the political and legislative reason for it, are both useless for the purpose of justifying construction by analogy.60 The third species, which we call particularly "ratio legis," is not contained in the body of rules itself but must first be discovered by the lawyer. It may therefore well be called a higher rule, or a "principium generate," a higher principle of which one or more of the existing rules of law are merely the results, or the logically deducible consequences.
57 Op. cit., Sec. 35.
58 The older theorists so define it. For instance, Dr. Eckhart in "Her-meneutica juris" (sect. 33) says: "Dialectica [i.e., logical] interpretatio in eruenda legis ratione versatur."
59 It is different in the philosophy of history.
Teachers of law assure us that it is possible to discover, by means of the logical operations of induction and abstraction, out of the legal rules actually before us, this original principle with scientific exactitude, and then, by the equally logical method of deduction, not only to revert to the legal rules from which we started but also to discover a number of additional rules of equal value.61 This process is said at no point to lose its strictly logical and exactly scientific character; consequently the new rules so discovered are represented as positive law, that is, law intended by the legislator, quite as much as the acknowledged rules from which we started originally. In this way, it is further asserted, we are enabled to avail ourselves of the newly found rules to supply law for the unprovided cases, without ever deviating from the rules of positive law, and thus the use of analogy is explained.62 To be sure, one is apt to ask at
60 linger, "System," section 10; similarly Thol, "Einleitung in das Privatrecht."
61 Comp. Thol, "Einleitung," section 55. According to him, it is the function of jurisprudence to find those legal rules which are not plainh-expressed. He believes that the ruling principle from which the rule follows is found by abstraction, and conversely, this principle may, by deduction or the drawing of consequences, be carried out into its details. Thus jurisprudence may determine in advance what the judgment must be when a corresponding case comes before the court. Next (sect. 64) he defines analogy as the discovery and application of a principle. Consequently he holds that construction by analogy is a logical deduction from the principle underlying a rule. It is purely a relation of premise and conclusion.
62 linger ("System") is so confident that this method is reliable as to say outright, in speaking of section 7, OBGB, and the law of nature: once: What then is the difference between analogy and mere broad construction, a difference on which so much stress is commonly laid, if it is true that analogy also serves merely to show what the legislator really meant, while it is admitted that the sense obtained by broad construction is not really contained in the text? We have already called attention to the confusion existing in this respect, and to the admission of it made by Pfaff-Hoffmann, after a thorough consideration of the subject. These writers fail, however, to draw therefrom the proper conclusions against the doctrine of a "ratio juris" and the customary theory of interpretation.63 For in their treatment of the functions of interpretation they still adhere to the methods of scholastic logic64; but where you employ that method, the doctrine of "ratio juris" is an indispensable makeshift for the defense of the use of analogy. This will appear plainly by putting the three following principal propositions side by side:
 
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