3.1 The Quest for a Legal A Priori

Among Reinach’s most central claims is the thesis that there is a legal a priori that constitutes the foundation of private law. It supposedly does not rest on experience but on the essence of legal phenomena. Therefore, a priori legal propositions are in his view independent of any particular legal system.

The chapter subjects this claim to a critical appraisal. Reinach challenges both positivist theories, which ground law solely in social acts without acknowledging a priori legal propositions, as well as those natural law theories according to which moral principles are part of the law. For Reinach excluded not only empirical propositions but also morality from the a priori foundations of law.Footnote ¹ This shows that the frequently maintained opposition between positivism and natural law theories is incomplete. Reinach’s theory, at least, challenges both.

Reinach uses a noteworthy example to show the a priori: the extinction of an obligation with fulfilment.Footnote ² He acknowledges that positive law can differ from such a priori propositions.Footnote ³ Thus, it would be consistent with his theory if, for instance, in times of need, the legislature mandated that certain obligations, like wage payments, should not disappear upon fulfilment but rather might have to be partially fulfilled again at a later point in time. According to his theory, such a case would not disprove the thesis of an a priori extinction upon fulfilment, as it pertains to positive law rather than a priori propositions.

This example of fulfilment is intriguing because, on the one hand, it seems indeed to be natural that obligations are extinguished through fulfilment: but, on the other, this extinction is not inherent in the concept of fulfilment itself. The latter only entails that what has been promised has been done. This raises the question of precisely why one can assume the extinction through fulfilment. How do we know this? Reinach’s answer in such cases seems to be that we can discern an a priori essence of this phenomenon.Footnote ⁴

But even if one grants that an extinction with fulfilment is self-evident,Footnote ⁵ it does not follow from this that it is a priori. This would presuppose that all obvious or self-evident propositions are a priori. For this purpose, one must demonstrate that no proposition derived from experience shares this characteristic. This seems to be an impossible task if one considers propositions such as ʻLegal norms are usually not completely implementedʼ. They seem quite plausible but still rest in part on empirical observations and are therefore not a priori. Hence, there seems to be no easy way to conclude from the fact that something is obvious to the fact that it is a priori.

Furthermore, it is not clear that propositions that rest on the essence of legal phenomena are indeed fundamental for law, as suggested by Reinach. It is at least theoretically possible to assume without contradiction that the law lacks a priori foundations but still contains a priori legal propositions which may concern only non-fundamental questions.

Reinach’s theory thus poses numerous challenges and raises a plethora of problems. Its core claim about the existence of a priori legal propositions is far from self-evident, considering the historical evolution of law and the diversity of legal systems. This chapter seeks to explore this claim. It looks at the main candidates for a priori legal propositions and discusses whether there are convincing reasons to assume their a priori character. If it turns out, as will be argued, that this is not the case, this does not completely disprove the existence of a legal a priori. There still may exist a priori legal propositions that have another basis. However, their scope is severely limited if the primary examples for such propositions turn out to rest in part on experience.

At the outset, some terminological clarifications seem appropriate. Legal propositions are in the following understood as true statements that could be made about law without implying their fundamental character. They regularly are – but need not be part of the positive law. A proposition about a certain object is a priori if one can justify its correctness without appeal to experience.Footnote ⁶ Its apriority can but does not need to be due to certain properties of this object but might also have to do with properties of the recognizing subject.

The definition of an a priori via justifiability remains neutral towards the question whether and how one forms a belief about a proposition.Footnote ⁷ It is thus independent of whether anybody came to know it and, if so, how they managed to do so. In this regard, one may or may not share Reinach’s position that one does not gain a priori insights through experience.Footnote ⁸ It is sufficient for the apriority that one can justify it without appealing to empirical evidence, even though this very evidence might be in fact necessary to become convinced of it. For instance, children might initially come to understand the correctness of a calculation only by counting with their fingers and remembering the result. However, this experience is not necessary to justify the correctness of a calculation. Similarly, one might only be able to grasp a proposition about a legal a priori if one is familiar with at least one positive legal system. Nevertheless, this does not prove that such a proposition is a posteriori, that is, that its justification rests on empirical observations. It might be the case that it is just human incapacity to discern the correctness of this proposition without knowing a particular legal system. Whether there is a legal a priori is thus an epistemic matter of justifying a proposition, not a cognitive one about belief formation.

To define an a priori proposition by its justifiabilityFootnote ⁹ without empirical evidence does not mean that a priori propositions are unrelated to those that rest on experience. Instead, it allows propositions derived from experience to support or refute a priori propositions, provided that the latter have independent justification to qualify as a priori. For instance, an a priori claim that no legal system can possibly contain a certain norm, say about timeless rights, could be refuted by providing an example of a legal system in which such rights exist. Nevertheless, the lack of such examples does not prove the claim’s correctness. For this, one needs a priori reasons.

Finally, apriority is to be distinguished from revisability.Footnote ¹⁰ While a sentence might be revisable due to the possibility of it being proven wrong through further investigation, it can still be considered a priori. For instance, mathematical hypotheses are open to revision because one could have made an error in calculation, yet they do not rely on empirical evidence and are hence not a posteriori. Similarly, even if one were to convincingly reject all Reinach’s a priori legal claims, it would not necessarily negate the possibility that there are a priori legal propositions. Reinach could have made a mistake in his examples, without being wrong about the underlying thesis concerning the existence of a legal a priori.

Unfortunately, Reinach hardly substantiates his concept of apriority. Although the a priori is the central concept of his thesis, he assumes that he does not need to deal with ‘the problem-laden theory of the apriori’Footnote ¹¹– thereby acknowledging its precarious character. Instead, he describes the a priori in various ways. In this respect, his remark is central that ʻevery state of affairs which is in the sense explained general and necessary is in our terminology aprioriʼ.Footnote ¹² But this leaves open whether necessity is the defining property of apriority or just its consequence. In the former case, a proposition is a priori in virtue of containing a necessary claim. Contrary to that, in the latter case the apriority is defined differently, for example by being justifiable without experience, and can nevertheless hold with necessity because only a posteriori insights might be contingently true.

Reinach’s cited description of the a priori has led some commentators to conclude that his concept of apriority relates not to cognition but to states of affairs and thus to ontology.Footnote ¹³ Reinach himself previously stressed that the necessity of the a priori pertains to the necessity of being and not of thinking.Footnote ¹⁴ However, the alternative of thinking or being is misleading. If the a priori relates to the justifiability of propositions, it neither concerns the act of thinking, as justifiability does not presuppose a conscious act, nor does it merely address how states of affairs are independent of us, as these acts alone do not determine what could count as a justification for us. Instead, the presence or absence of a priori justifiability of a proposition relates to what we should reasonably think under certain circumstances. This might very well be based in part on the properties of the state of affairs to which it refers. In this regard, one is indeed dealing with a ʻmaterial a prioriʼ. But in addition, one also deals with epistemic justifications for beings like us. Hence, the a priori concerns the justifiability of propositions about states of affairs and not just states of affairs themselves simpliciter. Thus, the a priori pertains both to being and thinking, which shows that the alternative is misleading.

The definition of the a priori as what one can justify without appeal to experience contradicts, at first glance, Reinach’s claim that ʻwhat is primarily a priori is neither sentences nor the judgment nor the act of knowledge, but rather the “posited”, judged, or known state of affairsʼ.Footnote ¹⁵ However, the use of the term ʻprimarilyʼ suggests that apriority does not only pertain to states of affairs, but also (‘secondarily’) to judgements and perceptions. The latter aspect aligns with the Kantian usage of the term ʻa prioriʼ, which formed the backdrop of much philosophical debate in the early twentieth century and, probably, also for Reinach.Footnote ¹⁶ According to this perspective, the a priori is not derived from experience but rather holds absolutely,Footnote ¹⁷ which is an epistemic and not an ontological claim. In this vein, Reinach maintains that a priori insights are, without any exception, capable of being based on irrefutable evidence and not gained through experience.Footnote ¹⁸ This shows once more that the necessity of an a priori proposition might not be its defining feature but its consequence.

Reinach’s theory can thus neither be confined to ontology nor to epistemology.Footnote ¹⁹ Accordingly, he emphasizes that a priori propositions do not stem from positive law,Footnote ²⁰ are self-evident,Footnote ²¹ or follow from an intuition of essences.Footnote ²² This mixes ontological claims (e.g., about lacking positivity), epistemic claims (e.g., about what is self-evident) and cognitive claims (e.g., about the role of intuitions).

When one attempts to defend Reinach’s thesis, several candidates of legal propositions come into sight that possibly are a priori. These are, following Reinach, necessary propositions (3.2) and essential propositions (3.3). Moreover, and independent of his views, non-positive legal propositions could in general be a priori, as they do not rest on propositions from positive law that can only be known a posteriori (3.4). If none of these candidates turn out to be a priori, the question becomes whether self-evident propositions, which were crucial for Reinach, still hold significance. Therefore, the chapter will conclude with the question of whether one can explain the phenomenon of self-evident legal propositions differently. I will argue that non-positive legal reasons provide for such an answer (3.5).

In this discussion, the chapter pursues a systematic approach to examine the plausibility of a legal a priori. It is thus not primarily concerned with an exegesis of Reinach’s text or with anchoring it in the phenomenological tradition, although such considerations might explain the boldness of his claims. Instead, the focus is on the persuasiveness of actual and possible arguments supporting his thesis of apriority. Thus, insights from current debates can play a role, without anachronistically accusing Reinach of ignoring them. For it might very well be the case that Reinach’s thesis of apriority is correct while his arguments for it are wanting. In order to assess his thesis, it is thus not sufficient to examine his own arguments. In addition, it is necessary to examine arguments Reinach himself did not use but which could, possibly, make his thesis of a legal a priori more plausible. By engaging in this way with later insights, Reinach’s work is treated with greater respect than if one were to confine oneself to its interpretation. Only in this way does his claim to have made timeless observations have a chance to become plausible.

3.2 Necessary Propositions

The primary source of a priori legal propositions in Reinach’s theory are necessary statements.Footnote ²³ According to him, the a priori is characterized by a necessity of being (and not of thinking).Footnote ²⁴ As already mentioned, he thus associates apriority and necessity by calling every state of affairs that ʻis general and necessaryʼFootnote ²⁵ a priori, although his comments also encompass epistemic notions.Footnote ²⁶ Regardless of Reinach’s stance, it appears, at least initially, to be a defining characteristic of a priori propositions that they remain unaffected by contingent circumstances and can thus not be contingently true. If true, they must be true by necessity. In contrast, a posteriori propositions hinge on such circumstances and therefore lack necessity.

For example, it is a question of positive law whether an obligation due for fulfilment becomes time-barred after three years. This depends on empirically contingent decisions of the legislator, which are not a priori given. In contrast, the proposition that an obligation generally is extinguished with fulfilment seems to be necessary. At least, no circumstances are discernible on whose correctness it depends.

However, from the fact that the content of positive law is both non-necessary and a posteriori one cannot draw the converse conclusion that legally necessary propositions are a priori. As Saul KripkeFootnote ²⁷ in particular has demonstrated, there can be necessary propositions whose correctness is not established a priori, but only follow from experience. He gives the example, already discussed in antiquity, that the morning star is the evening star, even if this can only be established by astronomical investigation and thus a posteriori.Footnote ²⁸ For the name morning star is a rigid denominator whose reference does not change once an object carries it and applies thus with necessity.

One can transfer this argument to law. For here, too, proper names serve as rigid denominators. Then only experience can show that they refer to the same object. For example, the fact that the German Basic Law and the current German constitution are identical does not follow from these concepts alone. According to its disputed original intention, the Basic Law could also be a mere provisional law – which is arguably no constitution.Footnote ²⁹ In order to establish the identity of the Basic Law with the German constitution, one must therefore examine whether both terms refer to the same law. This is now the case, since, according to Article 146, the Basic Law is no longer merely provisional. For this reason, the Basic Law is also referred to as the German Constitution. One is therefore dealing with different names for the same law. It is true that these names could have been different. But once they were chosen, they necessarily refer to the same object.

This example shows that, contrary to Reinach’s assumption, one cannot in general identify the necessity of a proposition with its apriority. Rather, there can be necessary legal propositions that are not a priori. The fact that one has to distinguish between apriority and necessity is not surprising; both deal with different issues. Whether something can only be known through experience is not the same question as whether something is necessarily the case.

This is of particular importance when one deals not with logical but with normative necessity.Footnote ³⁰ For example, a prohibition might rest on overwhelming legal or moral reasons that require it and that depend nevertheless in part on empirical considerations. In this case the prohibition is not a priori but still holds with (normative) necessity. Once all factual premises are known, it is even difficult to imagine that a normative conclusion does not follow with necessity, although it might be controversial, for there is no contingent fact that could make it only contingently true. This shows again that one can deal with propositions that are necessary and nevertheless uncertain. If their uncertainty can only be overcome with the help of empirical evidence, they cannot be a priori.

For instance, one might consider the proposition of deontological logic according to which a norm cannot simultaneously provide for a valid prohibition and a valid commandment of the same act A to be a priori plausible. In contrast, the necessity of normative evaluations might go back in part to empirical observations. Contradictory behaviour may be considered against good faith, if there is insufficient time within which others can adjust to the change. Whether something constitutes contradictory behaviour can therefore only be established with the help of evaluations of the period in which the change occurs. Nevertheless, the reasons for such an evaluation might be so strong that it is – despite its lack of apriority – normatively necessary.

Consider as an illustration the following case: It may be impermissible in a legal system on grounds of contradictoriness to initially release a photo for the press, but then to object to its use shortly before publication, while such an objection may be permissible after several years. So, it is not only contradictory to simultaneously allow and prohibit a certain action, but also to undertake both acts consecutively within a short time. The point at which behaviour becomes contradictory, and thus impermissible, may depend on empirical circumstances, such as whether an article or a print is usually prepared in a certain time. Thus, even the question of which acts are prohibited as contradictory, which seems like a good candidate for a priori legal propositions, does not, despite its normative necessity, rest entirely on a priori reasons. Therefore, the mere fact that overriding reasons necessitate a certain legal solution does not demonstrate that this solution is a priori. This may, but need not, be the case.

Note that this argument does not hinge on the distinction between an analytic and a synthetic a priori.Footnote ³¹ If this distinction breaks down, as QuineFootnote ³² has argued, nothing would change within it. Whether one can gain a priori insight by analysing a certain concept or whether one can synthesize different concepts into an a priori is independent of the distinction between (metaphysical) necessity and (epistemic) apriority.

Reinach’s identification of a priori and necessary propositions therefore seems to be rash. If one wants to prove a priori legal propositions, it requires more than just a reference to their necessity. However, it does not follow from this that there are no a priori legal propositions. They just do not follow from necessity alone.

3.3 Essential Propositions

For Reinach the existence of a priori legal propositions goes hand in hand with the assumption that there is an essence of legal concepts.Footnote ³³ In this perspective, it does not depend on the particular legal system what an a priori obligation or an a priori contract is. Rather, the concept is supposedly fixed from the outset, although the legal system can deviate from it.Footnote ³⁴ Concepts hence supposedly rest on essences, which are free from accidental circumstances that one can know only a posteriori. What lies in the essence of a thing shall be a priori. Conversely, what is a priori shall lie in the essence of a thing.

Against such a perspective, the accusation often associated with so-called conceptual jurisprudence of drawing legal conclusions from the concept or essence of a thing does not apply. For ReinachFootnote ³⁵ repeatedly and explicitly refuses to draw consequences for positive law from the essence of legal concepts and negatively refers to the temptation to do so as ʻontologismʼ. Consequently, he leaves unrestricted room for positive law to establish divergent concepts and norms according to expediency. When it comes to the capacity of the legislator, ReinachFootnote ³⁶ is a positivist, even though he wants to develop a profoundly non-positivist ontology of law.

In this way, Reinach tries to immunize the essence of legal concepts from the accusation that positive law foresees something else. In his theory, no a priori concept can fail for the reason that actual legal systems contain other forms of it. However, the question then becomes whether by shielding the fundamental concepts of private law from any positive law, Reinach has not thrown the baby out with the bathwater. What exactly is the essence of a legal concept if it is independent of any positive law so that no example of positive law can refute it? Such counter-examples are usually a good means to test the essence of entities, as they encompass those characteristics the absence of which would mean dealing with a different kind of entity.Footnote ³⁷ If, for example, one considers that one can sit on a chair to be one of its essential properties, then any chair on which one cannot sit would serve as a counter-example. Accordingly, if a property is essential for a legal concept, there should not be a single case to which this concept applies but in which the property is missing. Therefore, it would be natural to look at positive law for such examples in order to test whether a certain legal property is indeed essential for a certain concept.

Reinach excludes such a refutation in principle. He grants the legislator the freedom not only to use a different legal name for a certain phenomenon, but also the freedom to determine the same legal concept differently.Footnote ³⁸ Consequently, one cannot, according to his theory, find any counter-example in positive law against a priori concepts. It is therefore unclear on which basis one can establish or refute a priori concepts. For example, it is compatible with his theory that the legislature provides for non-consensual contracts. But how can one be certain that one is then still dealing with contracts and not with another kind of legal entity which the legislature merely calls ʻcontractsʼ? By opening up unlimited possibilities for positive law to deviate from a priori law, Reinach makes it doubtful how legal concepts could have any essence, as this by definition excludes deviations from it.

Likewise, the central question of how to determine the essence of a legal concept or entity remains open. Reinach defends himself against the accusation that a priori essence is something ʻdark and mysticalʼ, but then adopts the phenomenological terminology to ʻapproach the things themselves unburdened with preconceptionsʼ.Footnote ³⁹ How is that supposed to be possible for law? How can one approach an a priori right? After all, legal concepts are not like a house or a chair that one could physically approach.

Moreover, it is already unclear what evidence should support such an ʻunclouded viewʼ. Unlike material objects such as houses and chairs, of which one has an immediate sensory perception, law deals with ontologically ideal entities, which are frequently referred to as abstract objects.Footnote ⁴⁰ There cannot be a sensual perception of them. Hence, there is not even a sensual experience which one could take as a starting point in order to approach the essence of a legal phenomenon. For material objects such as chairs, one might try to determine what is essential by looking at many different specimens. In this way, one might determine, for example, that the colour of a chair does not belong to its essence, while there must necessarily be a surface intended for sitting on. However, precisely this starting point, which one can grasp by the senses, is missing in the case of non-empirical entities such as law.

One might examine different legal systems in a corresponding manner in order to establish an essence of legal concepts or institutions, as has occasionally been attempted in comparative law projects that search for a ‘common core’.Footnote ⁴¹ In this way, one could, for example, examine the concept of contract in ten legal systems in order to establish its essence. Yet this approach is opposite to Reinach’s,Footnote ⁴² because thereby one would only establish empirical commonalities in particular legal systems. There is no guarantee that these legal systems do not jointly deviate from the essence of an a priori concept. How, then, is one to arrive at a conclusion about such concepts if neither sensual perception nor familiarity with particular legal systems can help? How does thinking alone allow one to establish a legal concept?

One could attempt an analogy to mathematical propositions, since there is no sensory perception of them either, and one can also not derive them from particular calculations or other singular acts. As a priori propositions, the validity of which becomes clear merely by thinking, they could, possibly, serve as a model for a priori propositions in law. However, there is the difficulty that mathematical proofs result from axioms,Footnote ⁴³ which are set and not a priori recognized. The proofs are thus subject to certain assumptions and in this respect only apply hypothetically.Footnote ⁴⁴

Contrary to this, a priori legal propositions should apply unconditionally and not only contain hypothetical statements about what results when certain legal norms are valid. For instance, according to Reinach, the proposition that an obligation is extinguished by fulfilment should hold unconditionally and not depend upon the validity of certain positive norms. Mathematical propositions thus differ from legal propositions and hardly make a legal a priori plausible.

Reinach often refers to the fact that certain legal propositions are immediately obvious and self-evident, whereby he seems to rely on human intuition.Footnote ⁴⁵ In doing so, he picks up on a real phenomenon, namely that certain legal concepts and their interrelationships are plausible regardless of a particular legal system. The fact that an obligation is extinguished by fulfilment is intuitively obvious without one having to examine a particular legal system. The problem with this claim is not simply that one uses intuitions for the analysis of propositions.Footnote ⁴⁶ Rather, the problem is the claim of ʻthe intuitive grasping of them in an immediate insightʼFootnote ⁴⁷ and that there is ʻabsolute evidenceʼFootnote ⁴⁸ for them.Footnote ⁴⁹ For this suggests, against common experience, that one could not make mistakes about one’s legal intuitions concerning a priori propositions of law. What seems obvious at first glance might turn out to be wrong, so that it is questionable how absolute the evidence is on which Reinach relies.

Moreover, his underlying assumption that what is immediately insightful must be a priori is problematic. The source of human intuition is not necessarily accessible to the thinker himself, so that one can hardly know with certainty whether an immediate insight is a priori or a posteriori. Having an intuition does not mean knowing where it comes from. At best, further investigation can reveal this. One might simply deal with common sense, in which all kinds of insights, from experience and other sources, play a role. For example, if one considers it immediately plausible that an obligation will be extinguished through fulfilment, one’s own experiences with fulfilled obligations could play a role for this insight. It is in general by no means certain that an intuition is based only on a priori insights and not also – or even exclusivelyFootnote ⁵⁰ – on empirical experience. In view of the fact that one deals with legal norms in many ways in everyday life and that this, possibly, has an impact on one’s intuition about law, it cannot be ruled out that these experiences impact one’s intuitions about it.

Reinach’s claim that one can grasp the essence of legal concepts through intuition is therefore in tension with his claim that these concepts are a priori. The more one relies on intuition, the less one can be sure of gaining a priori insights, because one can then all the less exclude that one’s experiences play a role for one’s judgements. If, on the other hand, one only accepts propositions and concepts that are a priori, one must be prepared to exclude many of one’s intuitions because of their a posteriori nature. The danger in this case is that one must limit oneself to a few a priori statements of deontological logic, such as that a legal norm may not demand A and at the same time non-A. Then the more interesting legal questions, such as the consequences of the fulfilment of an obligation, remain out of sight.

The observation that language often, if not exclusively, shapes concepts supports this conclusion that intuitions are not a promising method for identifying a priori legal concepts. The fact that a contract presupposes the participation of at least two persons may simply be due to the fact that certain languages foresee such a concept. It is a long way from this fact to establishing that there is a concept of a contract independent of all languages that has certain essential properties. This requires bold conceptual claims about what is valid beyond any language.

If one refrains from making a judgement about such language-independent concepts, one can only determine what is essential according to the concept established in a particular language. As mentioned, essential properties of an entity are characterized by the fact that they cannot be absent without the entity falling under another concept. If one determines by intuition what is essential to a concept, one is possibly only stating a property of the concept that is established in a certain language, not a property that must also exist independently of any language. When Reinach refers to the intuition that certain statements about legal concepts are immediately obvious, this alone therefore does not prove the existence of a priori legal propositions. Possibly, his analysis only brings to light which properties of a concept are essential in a certain language.

The necessary characteristics of a legal concept within a certain language do not have to follow from a specific positive legal system, although its influence on language is indisputable, because legal concepts often differ in meaning from their everyday usage. Accordingly, determinations about what is essential for a concept can follow from the setup of a language without an anchor in positive law. This shows that legal concepts might occur in legal propositions whose correctness does not depend on a particular legal system.

For instance, according to the concept of a contract in many languages, it is part of its essence that at least two persons agree about it. If this is not the case, one is not dealing with a contract at all, but with another type of norm, such as a statute or an order. Other characteristics of a contract, on the other hand, are accidental, because they could be absent. For example, the fact that at least one party in a contract must pay money is an accidental property because, as in the case of exchange, there are also contracts in which neither side has to do that. The mere fact that such a distinction between essential and non-essential properties of a contract is plausible does not prove that this distinction applies per se and not only to a specific language. Its conceptualization might be contingent and thus, according to Reinach, an empirical question that eludes a priori regularities.

Once again, this suggests that Reinach may draw rash conclusions regarding the apriority of non-positive legal propositions, insofar as he relies on their obvious plausibility. Not only does it remain unclear how one can determine the essence of legal concepts and entities if neither perception through the senses nor experience with positive law is to play a role, but acquaintance with a particular language might also influence one’s intuition about legal phenomena. If this is the case, the relevant propositions are not a priori.

3.4 Non-positive Propositions

At first glance, one can infer a legal a priori from those propositions which, on the one hand, do not follow from positive law, but which, on the other, may nevertheless play a role in a legal argument. These non-positive propositions are able to support a statement about law without being traceable back to a social fact such as a legislative or judicial decision. In the absence of such a positive basis, they seem to be fixed for all legal systems and thus, at first glance, a priori.

The already mentioned proposition that an obligation is extinguished by fulfilment would be an example of such a non-positive proposition if one could justify it without referring to a legislative decision or another social fact. One might argue that the purpose of the fulfilment of an obligation is not only that the creditor receives what has been promised, but also that the debtor discharges his debt. If the obligation were not extinguished, he would have no reason to fulfil it. Moreover, the creditor would receive more than he was promised or to which he is entitled by law if the obligation were to persist after fulfilment.

These arguments do not rely on positive law, but nevertheless contain reasons that one could use in a legal argument. Does it follow from this that they are a priori, and can one thereby rescue Reinach’s thesis that there is a legal a priori although Reinach himself did not use such an argument? That would only be the case if all propositions that are not based solely on positive law must be a priori. Then one could conclude from the lack of positivity that a legal proposition is a priori. However, this conclusion appears doubtful. As the following discussion shall show, there are other types of non-positive and nevertheless non-a priori legal propositions.

3.5 Towards Non-positive Legal Reasons

It turns out, thus, that neither necessary (3.2), nor essential 3.3), nor non-positive propositions (3.4) prove the existence of a legal a priori. This raises the question of whether Reinach’s theory should be dismissed as interesting but ultimately unsustainable. That there are a priori foundations of law is after all not only the title, but also the central thesis of Reinach’s treatise.

However, such a conclusion would be premature. For the fact that the apriority of certain phenomena has not been proven does not mean that they are of no interest at all.Footnote ⁷² Maybe, Reinach was just too ambitious to explain them with an a priori, thereby excluding even the slightest empirical evidence. In this respect, it is worth returning to Reinach’s starting point. He begins by refuting the claim that all legal propositions and concepts are creations of positive law.Footnote ⁷³ Against this backdrop, he undertakes the search for a legal a priori. Rejecting this apriority does not mean, conversely, that all legal concepts and legal propositions are to be understood as positive law. As has already been argued,Footnote ⁷⁴ there are several kinds of plausible propositions about law that do not completely rest on positive law. Presupposed and morally based legal propositions are examples of them. They remain an important part of the law although they neither rest exclusively on positive law nor on a priori insights.

Reinach’s opposition to explaining legal phenomena with the help of positive law can therefore possibly be maintained without having to adopt his thesis of a legal a priori. This requires that one must explain the phenomena treated by Reinach without reference to an a priori. Whether or not this is possible cannot be decided across the board, as it requires an analysis of the particular phenomena treated by Reinach, which may be successful for some but not for other phenomena.

It should suffice here to look at the example that an obligation is extinguished through fulfilment. Such a claim becomes plausible if one looks for normative reasons that support it. In this regard reasons are understood in a broad sense as everything that helps to justify a proposition.Footnote ⁷⁵ They are normative if they count in favour of some action or attitude.Footnote ⁷⁶ Such reasons do not have to be independent of experience. For instance, historical insights about the fallibility of governments might be part of the reasons that are decisive for the design of the state. It is thus not plausible to assume that all reasons that support non-positive legal propositions are a priori. Reinach’sFootnote ⁷⁷ opposite view, possibly, is motivated by the fear that an established morality (‘positive morality’) can fail and is thus no reliable basis for law. However, his exclusion of all moral reasons from the foundations of law goes too far if it is to cover also those reasons that stand up to critical reflection (‘critical morality’).Footnote ⁷⁸ These include, in particular, minimal reasons as to which actions should be dismissed as obviously unacceptable.

For example, that an obligation disappears with performance, finds, as seen, its justification in the fact that the debtor would otherwise have no reason to perform, and the creditor would be unjustly enriched if he could demand performance again. The argumentative force of these reasons does not depend on whether there are certain positive norms about performance or extinction of obligations. Such reasons are thus non-positive.

Equally, the fact that an obligation is extinguished by waiverFootnote ⁷⁹ does not have to be attributed to a mystical essence that holds a priori. Rather, one can simply explain this extinction by the fact that the reason for an obligation is to provide a benefit to a particular person and that it is not an end in itself that such an obligation exists. Therefore, if the creditor decides by waiver not to receive the promised benefit, the reason why the obligation exists in the first place ceases to exist. Accordingly, it is reasonable for the law to order the extinction of the obligation in this case. One can understand the reasonableness of this proposition without referring to positive law.

The fact that there are such non-positive reasons for legal propositions does not mean that positive law always follows these reasons. As ReinachFootnote ⁸⁰ emphasized, the legislator is free to determine deviating norms. Indeed, what is reasonable is often disputed. Therefore, the legislator usually determines the law by an authoritative decision, even if it deviates from the non-positive reasons that weigh in favour of another decision. The dependence of private law on legislative determinations should not, however, lead to the conclusion that there are no non-positive legal reasons for private law propositions.

For such reasons to exist, it is by the stated definition merely necessary that there is something independent upon positive law that counts in favour of or against a certain action or state of affairs. If one considers that every action and most states of affairs have an impact on somebody’s freedom or autonomy, it is highly unlikely that there is nothing at all that would count for or against them. Therefore, it seems quite plausible that there are in most situations such normative reasons. This can also be seen in the fact that the difficulty of legislation and the accompanying discussions are regularly about which reasons are more convincing and hardly ever about the question of whether there is any reason at all for or against a certain proposal. The fact that a concept has a certain content and is related to other concepts is accordingly not necessarily a whim of positive law, but possibly an expression of a conception based on reasons. What is important about these reasons is not only that they do not refer to positive law, but also that their argumentative force is independent of it.

One might still ask whether such reasons are of a purely moral and thus not legal nature. In at least three respects this answer is negative. First, the fact that a reason is of moral nature does not exclude that it also states how the law should be designed and is thus to that extent related to law. This does not mean that propositions justified with the help of such reasons are necessarily valid law, but only that they at least should be valid law. In this regard, such reasons differ from those moral reasons that do not justify legal norms, for example because they concern decisions that should be left to the autonomous decision of individuals and thus not be legally required. Thus, unlike considerations that are decisive only for non-legal decisions, non-positive legal reasons are legal insofar as they take seriously the nature of law, that is, its specific characteristics.

Second, these reasons might not lead to a specific conclusion but might just justify why a certain distinction between two concepts or phenomena exists at all and is potentially significant in a legal context. In this case, these reasons do not justify legal norms but rather the concepts that should be applied within them, thereby highlighting the questions that must be resolved by a legal system. These reasons are legal insofar as they indicate the potential concepts and categories that a legal system could utilize. In the already mentioned example of contracts one can provide reasons for why contracts differ from one-sided decisions without thereby prescribing any legal consequence.

All of this does not mean that the law must encompass such distinctions. Instead, it elucidates why such a distinction exists in principle and why it might be relevant. These reasons concerning potential legal concepts are pivotal for legal analysis, although due to the lack of specific legal consequences, they do not constitute norms. Categorizing them strictly as either moral or legal would be misleading, as it would overlook the significance of having a well-developed terminology that can remain neutral regarding the legal consequences for which it might be employed. The categories, distinctions, and concepts that a legal system might use are at least to that extent legal in character, as a potential legal system might reasonably employ them, although this alone does not make them part of the positive law. For instance, there are convincing reasons to distinguish between contract and property, although a legal system might not draw this distinction.

Finally, non-positive legal reasons can rely on minimal preconditions, making their use in a legal decision permissible when there is no applicable positive law on point. The propositions justified with their help can then be legally binding as long as the legislature has not ordered otherwise. The fact that an obligation is extinguished by fulfilment, for example, is likely to be based on such minimal reasons. They are legally acceptable as long as positive law does not state otherwise. In contrast, many moral rules do not even have such a subsidiary character, because they are not based on minimal reasons and are thus incapable of justifying legal decisions. In this respect, minimal reasons that justify legal propositions might differ from general moral reasons.

The reference to the minimal character of these reasons shows that one must distinguish between different types of reasons – even among non-positive reasons that speak for or against a certain legal proposition. To treat them sweepingly as legal or moral is a misleading alternative and obscures such differences. The phenomenon emphasized by Reinach, that a number of legal propositions are self-evident, can be explained precisely by the fact that one is dealing with propositions that are justifiable by reasons that demand few preconditions and are thus minimal,Footnote ⁸¹ although they have no basis in positive law. What appeared to Reinach as self-evident might rest on minimal moral reasons that could and should be demonstrated.

In short, Reinach’s objective of uncovering non-positive elements of law remains a worthwhile project, especially when one looks at minimal reasons that underlie legal concepts, distinctions, and rules. First and foremost, these reasons help to explain self-evident legal propositions. In finding and characterizing non-positive reasons for them, one does not have to deny that in many cases it is controversial what these reasons precisely are. What is important at this point is only that such reasons might justify legal propositions in principle. The phenomenon of self-evident legal propositions emphasized by Reinach remains thus crucial, although his explanation with the help of an a priori is too ambitious to be true.