On Coherence
Notwithstanding the number, structure and content of the discursive rules and principles, another notion is worth introducing: the concept of coherence. This concept has inspired much discussion and disagreement in legal theory.
The problems mainly concern the notion of truth and its relationship to the concept of coherence (Habermas 1973, 212, 242, 252; Alexy 1989, 101; Rescher 1985, 169). According to Habermas, a proposition is “true” if, and only if, the validity claim with which we present it is justifiable. Further, that claim is justifiable if, and only if, people taking part in a rational discourse would agree with that proposition.Leonor Moral Soriano emphasises that the coherence of the legal system has to be kept apart from the coherence aspired for in legal interpretation or case-by-case applications of law and the related argumentation (Moral Soriano 2003, 296). The remark is important because the entire discussion of coherence conducted in the area of the theory of argumentation has exclusively concerned the compatibility of the grounds presented in support of the interpretative statement. The difference becomes apparent in the way Neil MacCormick describes the core content of coherence from the point of the common law system. His attention is focused, on the one hand, on the facts of the case and, on the other, the coherence between the principles and rules applicable in the matter. In this sense, it would be especially appropriate to discuss coherence on a “case-by-case basis”. On the other hand, MacCormick's idea of coherence is normative as to its nature. Some principles support a number of legal rules and make them coherent (MacCormick 1984, 235).
Ronald Dworkin's theory of integrity of law, in turn, includes MacCormick's view, but it seems to me to be more general. Dworkin compares the lawyer, when he builds up a coherent set of reasons, with a novelist participating in writing a (legal) “chain novel”.
Each novelist - that is, each lawyer - has an idea to make his additional remarks fit not only the general principles but all the material that has been included the precedents and value judgements. This means that Dworkin's idea of coherence is relative to the so-called narrative view of coherence (Dworkin 1986, 225). The weakness of this view concerns the criteria for coherence.As regards DSL, a few additional conditions concerning coherence are therefore important. They introduce the types of criteria one should take into account when deliberating on compatibility and coherence (Aarnio 1987, 120). The following criteria form a synopsis of a more detailed theory introduced by Aleksander Peczenik, partially in collaboration with Robert Alexy (Peczenik 1989, 159, 167; Alexy and Peczenik 1990, 13):
(1) The length of the syllogistic branches that can be presented in support of the arguments corresponds to the strength of the arguments. If, for example, reference is made to the government proposal, this is justified with the committee report in its background and the report with its own background studies, and the reasoning becomes stronger with each additional syllogism.
(2) The number of syllogistic branches used to strengthen the reasoning corresponds to the credibility of the presented statement. If, in addition to legislative history, the interpretation can also be supported with precedents, statements of DSL and practical arguments, it becomes stronger than any reasoning supported by only one chain of syllogism.
(3) The amount of networking among the different branches of the syllogism corresponds to the durability of the reasoning in question. Here, networking means that, for example, a practical argument branches off from law in the direction of economy, history, social relations or morality. Arguments of these areas do not need to have a direct connection with the legal problem being justified, but they do bring credibility to the arguments used.
The argument is “surrounded” by a network of arguments that strengthens its credibility.(4) The syllogistic chains used should be logically independent from each other. If there is a deductive dependence between the chains, one chain does not confirm the other.
(5) The most difficult additional condition for coherence concerns the relevance of the arguments. It is self-evident that the syllogistic chain should relate to the matter being disputed. The reasoning cannot be arbitrary. However, relevance is difficult to define theoretically. It is decided by the situation of reasoning, in which the relationship between the reasoned statement and the reasoning shows the degree of relevance. Irrelevant reasoning is excluded from the process of rational deliberation.
The degree of coherence, or its strength, depends upon the combined effect of the aforementioned preconditions. The longer, more voluminous and more networked the syllogistic chains supporting the argumentation, the more coherent the argumentation can be seen to be. The sufficiency of compatibility is, in the end, determined in the process of rational discourse case-by-case.
The problem of coherence can be elucidated with an analogy to a puzzle, being constructed as the game proceeds until the entire character is reached. There is, however, a decisive difference between the child's jig-saw puzzle and the “puzzlegame” of a scholar or judge. As far as the child's puzzle is concerned, the goal - that is, the final and proper character - can be identified on the cover of the game. This is not the case with the lawyer's “puzzle-game”. The lawyers, scholars included, build up the puzzle in the course of the reasoning. This causes a problem for reasoning based on coherence.
Whatever the combination of moves, and however these combinations are described, a question, already mentioned above, still remains open: When can the chain of grounds be broken? When are there enough pro-arguments to ensure the acceptability of the interpretation? Does such an ending even exist, or is it that an end actually exists but it cannot be recognised? In more general terms, the same question can be formulated as follows: How do we know that we have reached firm ground (a bedrock) on which to say that here, no more arguments are needed.
There are no other answers but one: it is impossible to define a clear borderline at which reasoning could, or even should, be broken off (Naess 1995, 220). The breaking of the chain of reasons depends on the totality of the chains, and, in the end, whether this totality is coherent enough in order to convince the other party of the interpretation.
This does not mean that we are “fundamentalists” vis-à-vis those who do not accept our view. All legal language-games are family-resemblent, so that the scholars dealing with a certain legal order can understand each other. They can even accept a lot of the arguments used by the other parties. Lawyers belong to roughly the same (or a similar) form of life. On the other hand, all members of a certain legal community do not necessarily share exactly the same basic assumptions. There are different audiences in a legal community. The “ending point” is connected to the rational acceptability achieved in a certain audience, and herein lies the basic rhetorical feature of legal thought.
To repeat, the chain of reasons can be “ripe for breaking” once the coherence of the reasons is sufficient. In this way, argumentation is always connected to the difference between internal and external justification, to the discursive nature of reasoning as well as to compatibility. Therefore, the theory of coherence is not only a sufficient but also a necessary element of the theory of argumentation.
The only “final point” is reached when all the parties are convinced of the sufficiency of the reasoning. The situation is similar to a hermeneutic circle. When trying to understand an action, event or text, one proceeds around the circle one round at a time in order to deepen one's understanding until no other information is necessary.