Ulpian and Natural Law

Brief Considerations on the Nature of Nature

The New Digest is pleased to present this guest post from Mr. Fernando Ferreira Jr. Mr. Ferreira is an attorney based in Rio de Janeiro. He holds a Master's degree in Regulatory Law from Fundação Getulio Vargas and specializes in public procurement law.

Classical natural law and the modern perplexity

When it comes to the classical tradition of law, few things are more perplexing than the definition of natural law (ius naturale) contained in the Digest. What is at stake is the definition given by Ulpian in fragment 1.1.1.3pr (translation by Alan Watson):

Jus naturale is that which nature has taught to all animals; for it is not a law specific to mankind but is common to all animals-land animals, sea animals, and the birds as well. Out of this comes the union of man and woman which we call marriage, and the procreation of children, and their rearing. So we can see that the other animals, wild beasts included, are rightly understood to be acquainted with this law.

The perplexity, which is mine and, I believe, also of many others who venture into this great treasure trove of wisdom from the classical texts, arises, among other things, from the breadth that Ulpian gives to his definition of ius naturale. What is striking is that natural law, as defined by the great jurisconsult, applies not only to men (as one would expect), but also to brutes, that is, to the irrationals. What are these teachings that nature transmits to all animals, including man, and which form the fabric of natural law itself? To put it more directly: how does nature teach anything to anyone, especially animals?

Add to this the fact that the definition of the great jurisconsult of Tyre makes no mention of the central element of the classical tradition of natural law, which is human reason. In this sense, Ulpian would have paid too much attention to the natural inclinations of human beings, and relegated man’s rational element to second place.

But, reflecting sine ira et studio on the issue, I think that an interpretation is possible that does justice to the jurisconsult’s definition. It is these modest reflections that I intend to share with readers of The New Digest over the next few paragraphs. I want to show, albeit in an inadequately limited and schematic way, that the notion of natural law recorded in the Digest has its raison d’être. But for this to become clear, it is necessary to place it in the appropriate philosophical context, proper to the classical tradition of natural law. Taken out of this cultural context, Ulpian’s definition loses its meaning and really becomes a source of perplexity, almost an insoluble enigma.

In addition, it must be seen that the absence of any mention of human reason in the definition proposed by Ulpian is not actually a problem. It’s just that this notion has to be read in conjunction with another definition also recorded in the first pages of the Digest, which is that of the ius gentium. Putting these two notions side by side (natural law and the law of the peoples) gives a complete picture (disregarding positive law for the moment) of the sources of law, or the raw material of law, that does justice to human reason. In other words: the definition of ius naturale is not exhausted in itself. In fact, it is completed and clarified by the notion of ius gentium.

The reason for perplexity

It seems to me that the perplexity is partly justified. It’s quite strange to hear that nature teaches animals and humans and, even more so, that this teaching, whatever it may be, constitutes a natural law that applies to all species. How can you not be astonished by such a statement? Some modern authors even call Ulpian’s definition scandalous. It’s as if Ulpian, when devising his definition of ius naturale, had paid excessive attention to the instinctive behavior of animals and considered their habits and routines as a type of law, that is, a natural law that would cover all living beings, rational and irrational.

In any case, there’s no need to be alarmed. The perplexity is perhaps resolved, at least in part, if we take into account the context in which Ulpian’s definition is given. I don’t think anyone is unaware that our view of the world, in the 21st century, is very different from that of Ulpian, a citizen of the eastern part of the Roman Empire in the 3rd century anno Domini. We have to bear in mind that the way Ulpian and his contemporaries, who were greatly influenced by Stoic thought among other factors, saw the world and nature around them is very different from the way we ourselves see and deal with the things in the outside world that surround us.

Since the end of the 18th century, roughly speaking, the Western mind has been immersed in a cosmology very different from that of the ancient and medieval world — a cosmology that would hardly have been recognized by Ulpian and his peers. It is a deterministic and mechanistic view of the Universe that, among others, was popularized by Voltaire (Élements de la Philosophie de Newton, 1738).

Be that as it may, the most central and salient feature of this tradition, at least for what interests us here, is what is known as bifurcationism: the tragic division of reality into res cogitans and res extensa or into the world of phenomena and the thing-in-itself. This ontological break in the unity of the world — a spurious Cartesian feature — will lead to the development of a parallel division of the sciences: on the one hand, the sciences of nature, which focus on studying the phenomena of the outside world; on the other hand, the so-called sciences of man or of the spirit, which deal precisely with those phenomena that concern human creativity, culture, religion, etc.

In the field of ethics and law, bifurcationism will manifest itself in the irreconcilable separation between being and ought-to-be. A whole tradition of thought, materialist and positivist, will develop from this. While the natural sciences are descriptive, the human sciences (ethics, law, etc.), on the other hand, are normative sciences, since their object is the ought-to-be. They therefore depend on norms. However, there are no norms in nature: it tells us nothing, much less teaches us. Nature is nothing more than brute and blind necessity (ananke), an inflexible determinism with no value in itself.

In this context, Ulpian’s definition (“ius naturale is that which nature has taught to all animals...” etc.) really makes no sense: how could blind necessity teach anything to anyone? Nature in itself has no value, and no norm or valuation can be drawn from it. You can’t go from being to ought to be: Ulpian is guilty of the grossest naturalistic fallacy.

Another nature, another world

We can assume, with relative certainty, that the world of Ulpian and his peers was very different. If we take Aristotelian physics as a reference (and I see no reason to take another reference, since the expression natural law, dikayon physikon, is itself from Aristotle), we are in a completely different context from the mechanistic-deterministic materialism of positivist-type conceptions.

It is not the case here to make an exposition of classical physics (or metaphysics), which is certainly out of my reach, but only to outline some principles that will allow us to understand, with a little more generosity and benevolence, the definition of natural law given to us by Ulpian.

The first of these principles: contrary to common sense, when we talk about nature, we are ipso facto talking about movement. Nature, in its classical sense, is the world of things that themselves have the principle of movement. And movement here must be understood not just as local movement, i.e. displacement, but as any kind of transformation.

But where does this movement come from? What is the reason for it? The second principle: there is a tension of change and transformation inherent in everything that exists in the world of nature. This tension is the result of the fact that everything in nature is made up of matter and form. Matter is the blind, brute necessity, the power of transformation, the mechanical element of reality. Form is the intelligent component, the reason for being. Form is the perfection of the thing: it is the thing fully realized, i.e., made into what it is (should be) in fact and in truth. There is a whole metaphysical dynamism involved in the transformations of being: it is not the juxtaposition of two heterogeneous elements: “it is a spontaneous creation of being and perfection”.

Third point: the fundamental principle of classical (Aristotelian) physics is that God and nature do nothing in vain. This means that everything that happens in nature, that all movement is always, as far as possible, towards an end. Chance is the exception. Nature, precisely because it always seeks an end, almost always tends to do what is best, to produce what is most beautiful, orderly and harmonious.

So what is nature? Nature is the final cause. It is the form that acts on indeterminate matter. And the end, in turn, is nothing more than the form, because the end to be achieved by the movement of being is the full and perfect realization of the form towards which that movement tends. In other words, the things of the world of nature have an end towards which they are moving. And this end is a form.

Therefore, unlike modern natural science, which sees nothing in things other than the presence of abstract mechanical laws with no meaningful purpose, in classical natural science the movement of things is explained by the presence of final causes:

The life and growth of a plant can only be apprehended according to a finality, according to its native orientation to become a tree, to produce flowers and fruits (and maybe the fruits are to nourish man). The life and movements of animals can only be apprehended in relation to their tendency to preserve themselves, nourish themselves, preserve their species. Their acts cannot be explained by the mere mechanical effect of efficient causes as Descartes imagines; they appertain to another kind of order governed by final causes.

Bonum in re est

The things of nature move in a certain direction. They seek to realize, as far as possible, the form which, in turn, is the end, the desired telos. And achieving this telos, that is, the full realization of the form, is in itself the good. As St. Thomas Aquinas emphasizes, every agent necessarily acts for the sake of the good.

In short, still in the line of thought of St. Thomas, all things, as long as they have being, have something good about them. Ens et bonum convertuntur: this means that these terms, good and being, are basically the same thing. Existence in itself is good, and evil can only be conceived as a privation, a deficient form of existence. Evil does not exist as a substance, only as a quality, or rather, as a lack of it. The good is not something that people attribute to things: it is inherent in things themselves, as a final or formal cause. Bonum in re est: the good is a fact of reality, an element of reality. It is not a human construct: the good is in things, in their movement, independently of human will.

Classical natural law in its proper context

I apologize for the previous paragraphs. Although to some extent tedious, and grossly sketchy and incomplete, the exposition of some rudiments of classical physics was necessary so that we can have a notion, albeit vague, of the context in which Ulpian’s definition is inserted.

I want to believe that Ulpian’s words now make a little more sense. Nature teaches animals: all of them, including men. This teaching shouldn’t be surprising. From the classical perspective, nature is the final cause that moves all beings towards a certain goal. This goal is the full realization of form: the passage from potency to act. It is in this sense that nature teaches: it directs, guides, in short, leads beings towards their respective perfections. Natural law is in things, it is in the reality of the relationships between beings. Or rather: there is a tendency in things to realize it, i.e. to move from potency to act.

Put this way, there is no reason to be surprised by Ulpian’s definition. Natural law encompasses all beings. According to St. Thomas, all creatures share in God’s eternal law. It just so happens that in irrational creatures this participation is not an active participation, so to speak. What they have, strictly speaking, is an impression (“inquantum scilicet ex impressione eius habent inclinationes in proprios actus et fines”): the eternal law is as if imprinted on these creatures, instinctively inclining them towards their own acts and ends.

The case of men is different: what happens here is actually a participation in the proper sense, insofar as they are rational creatures. And this is because men are, in a certain sense, co-authors of divine Providence, providing for themselves and their neighbors.

Be that as it may, in either case, this participation of all animals in God’s eternal reason is natural law.

The place of human reason

Even so, Ulpian’s definition sounds incomplete. It makes no mention of human reason. At no point does it refer to the rational element of natural law.

We saw above that men participate in God’s eternal reason (the lex æterna). And that this participation is natural law. But what is interesting is that animals, irrational creatures, also participate in this same reason and are therefore also governed by natural law. The difference is that they are governed differently from rational creatures. In both cases, there is a participation. The difference is that, in the case of men, this participation is active, while in the case of irrational creatures, it is passive.

The big problem is that Ulpian’s definition doesn’t seem to point to any solution. Worse still: the great jurisconsult of Tyre shows no sign of having grasped the issue.

But the situation is not what it seems. Or at least, that’s not how I see it. If we look a little further into the text of the Digest, we can see what I believe to be a glimpse of a solution to the problem before us. I especially suggest that we look at the following fragment, which deals with the ius gentium (the translation is by Alan Watson):

4. Jus gentium, the law of nations, is that which all human peoples observe. That it is not co-extensive with natural law can be grasped easily, since the latter is common to all animals whereas jus gentium is common only to human beings among themselves.

The modern canonical interpretation is that ius gentium, or law of nations, is a kind of prototype or incipient version of international law. Hence the translation of the expression ius gentium into law of nations.

However, this may not be the best understanding of the text. Perhaps the modern interpretation of the expression as an antecedent of international law is spurious, having departed from the original meaning. What makes me think this, in the first place, is the reading of Gaius. Gaius, in his Institutes, when referring to ius gentium, does not imply that it concerns relations and exchanges between different nations and peoples. In fact, what we see there is that the ius gentium is the typical (i.e. natural) law of the human species: “...while the law that natural reason establishes among all mankind is followed by all peoples alike, and is called ius gentium (law of nations, or law of the world) as being the law observed by all mankind” (translation by Francis de Zulueta).

Following the Digest, the institutions that the jurisconsults attribute to the ius gentium are natural to the human species in general. Pomponius speaks of religious and filial duties. Florentinus, for his part, speaks of the right of self-defense. Hermogenianus refers to the foundation of kingdoms and nations, the right of property, contracts, etc. All institutions that are natural, not to animals tout court, but only to the rational animal: ius gentium is the natural law proper to human beings, since it derives from the natural reason of the species (“...the law that natural reason establishes among all mankind...”).

The final answer, however, comes from St. Thomas. In article 3, question 57 of the Summa Theologica, in the Treatise on Justice, the great Dominican saint deals with the distinction between the ius naturale and the ius gentium. And there, in St. Thomas’ treatment of the quæstio, there is not even a glimpse of an approximation between the ius gentium and what was later called international law or anything of the sort.

Quite the contrary, and without going into greater detail here, what we can see in this question is that St. Thomas is dealing precisely with the way of knowing the natural law. That is to say: it is no longer a question of whether natural law exists (the object of the previous question), but rather of how it can be known by men. An epistemological question, so to speak. In this case, there are two possibilities. The first is the absolute mode of consideration of the thing (“...secundum absolutam sui considerationem...”). The second is the relative way of considering the thing, in view of its consequences (“...sed secundum aliquid quod ex ipso consequitur...”). In the first case, knowledge is common to both men and animals. Hence natural law, which covers all living things without distinction. In the second case, what is at stake is a mode of knowledge that concerns only human beings: it is typical of men to know things by comparing them with their consequences (“Considerare autem aliquid comparando ad id quod ex ipso sequitur, est proprium rationis”). And this specifically human knowledge of natural law is what classical tradition, and St. Thomas eminently, will call ius gentium.

So, if I’m not far wrong, I think it’s possible to say, with a good deal of certainty, that the ius gentium, quite the opposite of being a precursor to modern international law (an idea first advocated by Vitoria and other peninsular scholastics), is in reality the very mode of human knowledge of the ius naturale. In other words: ius gentium is the result of the gradual process of learning about and revelation of ius naturale: a kind of slow, gradual and progressive development of the doctrine along the lines of St. John Henry Newman. Man, through his reason, unveils natural law little by little. The consequence of this progressive unveiling and development is what the classical tradition calls ius gentium.

Nature does indeed teach all animals, but it teaches humans in a slightly different way. This different way, adjusted to natural reason, is ius gentium.