A brief take on Xavier Zubiri's metaphysics
I've decided to finally get started on trying to explain what I call "Zubizantine theology," a combination of Eastern (Byzantine) theology and the metaphysical formulation of Xavier Zubiri. Zubiri is a Catholic philosopher, a laicized Jesuit who did most of his teaching at seminars in Madrid in the early 20th century. He managed to continue teaching even during the anti-Catholic persecution of the Spanish government during that time by earning a favorable impression of a well-placed government official, so that Zubiri ended up being able to conduct private seminars despite being unable to teach at the University of Madrid. This suited Zubiri's pedagogical style quite well, as he preferred the seminar format himself, but the drawback was that he was relatively unknown even among the academics of his time and that the excellent texts produced from his seminars have languished untranslated in Spanish (a problem common to numerous Spanish philosophers that is lamented here by LMU's own Dr. Brad Elliott Stone). The good thing about Zubiri is that he was consciously attempting to recover a patristic and a Catholic mindset in his metaphysical efforts, so his efforts mesh quite smoothly with attempts to reconcile Western theology with its Eastern heritage. In that regard, he also harmonizes with the thinkers such as Maurice Blondel who strongly influenced the conservative side of Vatican II theology, although he clashes significantly with some aspects of neo-Thomism and Thomistic theology in general.
The most impressive aspect of Zubiri's thinking is the sheer breadth of his training. Not only was Zubiri trained in a vast array of subjects, but he was trained by some of the best practitioners of those subjects in history. To give just a few examples, he studied philosophy under Husserl and Heidegger, physics under de Broglie and Schrodinger, and classical philology under Harvard professor Werner Jaeger, to say nothing of his training in theology, patristics, history, mathematics, and biology. Few scholars have ever achieved that much expertise in so many diverse areas of intellectual endeavor, and of those who have, Stanley Jaki is probably the only one with whom most Catholics will have much familiarity. But what impresses me most about Zubiri is not his expertise, but his unparalleled ability to synthesize these diverse areas of thought coherently, an achievement that conjures images of such Christian luminaries as the Cappadocian Fathers and St. Thomas Aquinas.
Generally, I would say that Zubiri approaches metaphysics from a phenomenological perspective, in that he starts from the immersion of the person in reality and the "power (dynamis) of the real," the sensation of reality undeniably impressing itself on the human consciousness. From that premise, he derives his theory of "sentient intelligence," which I will not demean by attempting to explain in its entirety here except to note that it departs rather strongly from Aristotle's notion of hylomorphism (the form impressed on the mind by sensory information), despite bearing some superficial resemblances to that idea. Instead, to skip ahead to ontology, Zubiri takes Husserl's idea of "notes," observable features or characteristics of things, and digs down beneath it to the underlying reality by first noting that, paradoxically, one cannot get to the reality! Much like the Cappadocians could make an argument for the unknowability of reality by recourse to the complexity of a single ant, Zubiri argues that reality cannot ever be fully exhausted by investigating its notes. On the contrary, reality is inexhaustibly fecund, which gives to Zubiri his formulation of reality as dar de si (giving of itself), and apophatically defeats all attempts at the "entification of reality" (confusing reality with being, i.e., existence of notes) or "logification of intellect" (description of reality in terms of concepts, such as a "nature" being "genus and species").
In recapturing the fundamental incomprehensibility of reality, Zubiri is really appealing to the same Christian tradition of the Cappadocians that was used to defeat pagan rationalism. Where Zubiri takes things a step farther is in his introduction of an entirely new metaphysical concept of reality: that of reality as structure. Zubiri recognizes that even the most simple object is revealed by science to be an incredibly complex structure, literally billions of atoms interacting with one another. Moreover, even at the smallest scale, it is impossible to identify the tiniest parts of matter with absolute certainty in absolute separation from anything else, because of the quantum mechanical nature of reality. Thus, Zubiri maintains that the notion of "subject" as a purely autonomous thing existing of itself in which qualities inhere simply will not do, and this is the error that has plagued classical philosophy from its inception, all the way back to Parminides. Instead of thinking of reality as autonomous subject, one must instead think of reality as structure. It is not the notes themselves, but the coherence of notes with one another, that make a reality in its own right (de suyo), and the degree to which reality is de suyo is its substantivity. It is important to note that reality is never entirely de suyo, entirely unconnected from other reality, but it is a matter of degree. Moreover, the structure of reality is itself organized at different levels (atoms form molecules; molecules, cells; cells, organs; organs, organisms; etc.).
From substantivity, one can proceed to the notion of essence. An essence in Zubiri's terminology would roughly correspond to a "nature" in classical philosophy, but dealing mutatis mutandis with substantivity rather than substance. Thus, it is a structure that is uniquely its own in its interaction with reality. And because reality itself has levels, essences can have levels as well (so that the arrangement of particles in gold atoms could suggest the essence of gold, while a collection of those atoms in a particular arrangement can define a coin). One could rarely (if ever) entirely exhaust the concept of essence for any particular structure, which simply reflects that reality itself is self-giving beyond comprehension. Still, it does not mean that one cannot say meaningful things about structures, only that one is never going to say everything that can possibly be said about them.
In Zubiri's mind, essences can be closed or open. In a closed essence, the coherence of the notes, the way the structure behaves, is rigidly bound to their particular substantivity. They are what they are, so to speak, and breaking the structure causes the thing to be not what it is. This is generally true of inanimate objects, for instance, so that if a molecular structure is broken, the thing fundamentally ceases to be what it is. Open essences, by contrast, can appropriate reality and make it their own. "Their own" is not a bad term for open essences, because the classic example is a living thing, which can appropriate other realities into its own substantivity by breathing, eating, metabolizing, and the like (or more generally, by taking action rather than being acted upon). At the very pinnacle of the open essences is man, the "animal of realities," who goes so far as to actually make choices that define his own reality by his experiences. It is this fundamental quality of "his-ownness" that defines personhood in Zubiri's metaphysics, a distinction that will prove extremely useful in its Christian applications to both theology and anthropology.
I hope that will provide an adequate introduction, but if anything is unclear, feel free to email me or (even better) to check out the links I've provided, which do all of these subjects far more justice than I have. I'm just trying to set up the background sufficiently to discuss some of the theological points meaningfully, and if I manage to accomplish that, I'll be happy.