The Great Paradigm Shift: Xavier Zubiri and the Scientific Revolution, 1890-1990

Author: Thomas B. Fowler, SC.D.


Thomas B. Fowler, SC.D.


The world of science at the end of the 19th century enjoyed a deceptive tranquility. Thoroughly grounded in philosophical notions of causality and determinism from the Greeks, and bolstered by the British Empiricists, it boasted the grand and intuitively satisfying infrastructure of Newtonian mechanics and the great edifice built thereon by Newton and his illustrious successors, among them Laplace, Lagrange, and Hamilton. The theory of electricity and magnetism was well understood; and the first great unification work of physics had been completed by Maxwell in his celebrated equations. The atomic structure of matter had been worked out by Dalton, Lavoisier, and others; and the unfolding of the biological world was revealed by Darwin. Nor was all of this just a theoretical enterprise; rather, it spanned the full range of human interest: celestial mechanics had unlocked secrets of the heavens, and the face of Europe and the New World were being transformed by engineers trained in the new science. So confident, indeed, were the purveyors of 19th century science that their Weltanschauung was enshrined in Laplace's famous demon: an intelligence which knew the position and momentum of all particles, and so with the help of Newton's laws, could predict the entire future course and retrodict the entire past history of the universe. Even in mathematics, an exuberant Hilbert believed that an axiomatic foundation for all of mathematics could be created.

There were disturbing cracks in this edifice: thermodynamics was plagued with difficulties involving infinities, such as the absolute value of entropy and the "ultraviolet catastrophe"; electromagnetic theory could not be reconciled with the emerging picture of the atom; the Michalson/Morley experiment disclosed problems with Newtonian absolute space and time; and Poincare's work on the three-body problem in celestial mechanics indicated that highly disordered behavior could result from simple mechanical systems and deterministic Newtonian laws. Russell's paradox hinted that all was not well in the foundations of mathematics. Still, few if any suspected the storm about to be visited upon science in the new century, a storm which would overturn virtually every cherished idea upon which science was thought to be based. In the process, it would call for an heroic and radical rethinking of philosophy and its interactions with science, a rethinking which would require someone of great genius, with a thorough grounding in philosophy and its history, in theology, in science, mathematics, and much of the rest of human knowledge. But perhaps most importantly, someone with the deep and abiding desire to penetrate to the truth by encompassing all of this knowledge in a comprehensive vision, and to create the foundation for a new synthesis of human knowledge, one which could integrate the reality delivered to us by science with the rest of human knowledge. The world is indeed fortunate that such a man was born at the critical time, in 1898, in Spain, a country with a deep and rich cultural, educational, and spiritual heritage.1

Science and Nature in the 20th Century: The Collapse of Reductionism

Reductionism has been a strong undercurrent throughout the history of science as well as philosophy. Laplace's Demon is, in a sense, the ultimate expression of it and thus of classical physics and 19th century science in general. The goal, as Zubiri2 and others have pointed out, is to reduce biology to chemistry, chemistry to physics, and then, knowing the ultimate particles and the most fundamental laws, together with the necessary initial conditions, rebuild all of science and, by implication, of reality. The dogmatic nature of the identification of science with reductionism and strict determinism may have been apparent to 19th century scientists and philosophers; but since science was inconceivable otherwise, there was little serious discussion of the matter. A commonly drawn corollary is a radical realism: the world really is made up of the ultimate particles and the laws governing them; even God perceives the world this way. Hence, for theologians, reductionism tended to mean that the laws of physics were the "mind" of God, who thus was turned into the super physicist—ironically, the ultimate realization of Laplace's Demon.3

The first blow was struck by Einstein in his Special Theory of Relativity (1905), which disclosed that Newtonian absolute space and time were, at least for scientific purposes, chimerical. The paradoxical results stemming from the failure of simultaneity and the relativity of time gave clear warning that intuitive ideas from classical physics and much of philosophy were headed for rough seas. Still, determinism and reductionism appeared to be intact.

Development of quantum mechanics a scant 20 years later was the fatal blow. In place of the familiar absolutes of position and momentum, Schrodinger's equation yielded as its solution a wave function which gave only probability distributions for these quantities. Worse, Heisenberg's Uncertainty Principle revealed a complementarity between position and momentum, and between time and energy, such that the product of uncertainties in them had a lower bound (Op. Ox>h). The new edifice of physics built upon this foundation, including such paradoxes as the interference of single particles, tunneling, the concept of virtual particles, and quantum activity of the vacuum, has been verified to an extremely high degree by experiment and has permitted physicists to construct vast theories describing the creation and evolution of the universe, going back to the limit of Planck time, 10-43 second after the Big Bang. There is in fact a double blow to classical ideas of science: first, deterministic laws are replaced by statistical laws; and second, exact boundary conditions are in most cases replaced by boundary conditions with a lower bound of uncertainty. This latter is particularly important because it means that even with deterministic laws strict reductionism is impossible, and therefore implies that complexity in the world must be irreducibly hierarchical.

Early on, Zubiri understood the profound change which had occurred, and moreover, realized that it was not a degradation of science, but a giant purification step which freed science from its unnecessary (and probably false) metaphysical baggage:

So, not only is it untrue that the idea of cause gave rise to modern science, but in fact modern science had its origin in the exquisite care with which it restricted this idea. That renunciation was, for the representatives of the old physics, the great scandal of the epoch. How is it possible for physics to renounce explanation of the origin of all movement? This heroic renunciation, nonetheless, engendered modern physics. Hence it is not permissible to whisper of scandals in the face of Heisenberg's principle; it is rather necessary to faithfully examine the situation and see if it does not give to physics its ultimate stroke of purity.4

Of course, the advocates of determinism in science did not take kindly to this radical reinterpretation of nature. They refused to believe that (their) "God plays dice with the universe"5 and therefore postulated the incompleteness of quantum mechanics and the necessity for "hidden parameters" to restore determinism.6 With Einstein himself at their head, they leveled attack after attack, only to be beat back by Heisenberg and others. Their criticism culminated with the Einstein-Padorsky-Rosen (EPR) paradox, postulating a certain experiment the outcome of which would differ depending on the determinism or indeterminism of reality. Thirty years later this led to Bell's inequalities and thence to the famous experiment by Aspect and his group at the University of Paris in 1982.7 The pivotal nature of this experiment for both science and philosophy can scarcely be overestimated: in it, 2500 years of thought about the nature of reality came together. It was a test not just of determinism vs. indeterminism, but also of the so-called "non-locality" of nature, i.e., of the virtual interconnectedness of the entire universe—even things at opposite ends of it—which act as if they were as close as you and I in this room today.8 The outcome was quite clear: the universe is indeterministic and non-local, at least as far as measurement is concerned. The profound impression left by the Aspect experiment is of the inadequacy, the ultimate limitations of the human mind in perceiving the ultimate truth about reality, and of the complete futility of assuming that the laws of physics can in any sense represent God's way of knowing the universe. Nearly 50 years earlier, Zubiri had already perceived it: "For God, not only is there no physics, there is no Nature in this sense either."9

But the ultimate disaster for classical physics (and the 19th century world view based upon it) may turn out to be the rediscovery in the 1960s, 70s, and 80s of what is now termed "chaos theory": the existence of simple, deterministic physical systems, obeying Newton's laws, which nonetheless exhibit behavior so irregular that it is, for all practical and experimental purposes, stochastic and unpredictable.10,11 Chaotic behavior was originally discovered by Poincare and Bruns around 1880 in their investigations of celestial mechanics and the three-body problem, but was ignored at the time because it did not fit the then-current paradigm of science, viz. that simple systems evolving in accordance with Newtonian physics had to exhibit regular, predictable behavior. What is the sense of a science which cannot make exact, testable predictions? Or worse, for nature to behave chaotically in some fundamental sense? Irregular behavior, if observed, was regarded as the result of random noise or other interference. If physical laws were the mind of God, how could they yield anything other than order?

The irregular behavior is real enough, however, and can be readily viewed on a simple personal computer and has now been observed in many real systems.12 Moreover, as Poincare discovered, it characterizes the simple three-body problem, and a fortiori the n-body problem, which describes how the solar system will evolve with time. The somewhat disconcerting conclusion is that the long-term stability of the solar system cannot be guaranteed.13 For purposes of the present discussion, however, the key point is that even deterministic laws are insufficient to guarantee ordered behavior,14 and thus the long-standing belief in the mutual implication of causality, ordered behavior, and deterministic laws has broken down. Though Zubiri was apparently unaware of the emergence of chaos theory, he had already foreseen its implications:

Indetermination seems to be what is most opposed to the character of all scientific thinking . . . to renounce determinism would be to renounce causality, and with it, everything that has constituted the meaning of science from Galileo up to the present day.15

But in fact, as Zubiri perceived, science understood in such terms was in reality a mixture of pure science and spurious metaphysical notions,16 and that causality is a much broader concept than determinism: "Causality is not synonymous with determinism; rather, determinism is a type of causality."17 Forty years later he made an observation that is particularly relevant to chaotic system behavior:

Above all, the fact that an effect may have reality in virtue of a cause does not mean that either the effect or the cause are repeatable. That is, Determinism is ultimately a schema for a type of causality, but not causality itself.18

Even without the Aspect experiment, chaos theory would have spelled the ultimate demise of classical notions of science because it strikes so much at their heart.

A fourth major blow to classical ideas was contemporaneous with the development of quantum mechanics; but since its implications were more difficult to perceive and somewhat less threatening, it did not receive widespread publicity at the time. This is of course Godel's Theorem. The meaning of this theorem has been debated for 60 years; but one fact is incontrovertible: our understanding of the nature of mathematics has changed radically. Prior to Godel, it was possible to identify mathematical truth with provability; this is no longer possible: truth is a broader concept. Mathematics and formal systems in general are thus much richer than previously suspected, and our understanding of them will always be more limited than was thought by Hilbert. This is the aspect of the theorem which Zubiri regarded as most significant, because it reveals that our knowledge even of postulated realities can never be complete; they like all reality are open in a fundamental way.19

Zubiri himself recognized that collapse of reductionism was inevitable in light of scientific developments of the 20th century, and he clearly stated the philosophical reasons why it was untenable:

It would be a great error to think that the transcendental structures of being depend only upon the structure of electrons or inanimate matter. We always tend to believe, when alluding to love or persons, that we are speaking of things anthropomorphically and metaphorically; and that what really matters are the electromagnetic fields and the electrons. But why? Are these other things not realities? . . . Very different are the dynamic structures of local movement, of physical phenomena, of a living thing, of a human person, to say nothing of history and human society as a whole.20

The Rise of the Systems Approach

From a practical standpoint, science has long recognized that a hierarchical approach to knowledge is indispensable. One need only examine the breakdown of scientific disciplines and the manner in which science is taught to verify this: a chemist developing vaccines may know little about the theory of quarks, a physician treating a bleeding patient may understand little of fluid mechanics, and a computer programmer programming insurance software may never study solid state physics. Increasingly it is becoming apparent that this practical approach reflects an underlying reality, viz. that what is important is the components of a thing at a given level and how they interact, i.e., the system, rather than an ability to predict everything based on the lowest hierarchical layer.21 Reflecting this paradigm shift, there is now a rapidly growing science of systems, which concerns itself with how interaction takes place, and what behavior systems can exhibit. Included are studies of connectivity, stability, and control.

This new systems approach assumes that reality as perceived by finite entities (not necessarily animate) is layered, with each layer's behavior constrained by, but not fully determined by the lower layers. Why? Physically, it is because at each layer there are uncertainties owing to uncertainties at lower layers, and the impossibility of determining the total set of interactions of things at those lower levels. Drawing a clear distinction between causality and cause, Zubiri has incisively noted that causality is the functionality of the real as real,22 and is perceived by the sentient intelligence.23 But the matter of finding causes for a particular phenomenon is exceedingly difficult and problematic:

Who can ever be sure of having discovered a real cause of a phenomenon, much less, maintaining that this cause is adequate? This is absolutely chimerical.24

To use Zubiri's example, if I pull the cord of a bell, the bell rings. Is this the cause? Suppose the bell were moved to the moon. Then a pull on the cord would produce no sound. Causality as perceived by a sentient intelligence is functionality, which may occur in many forms; it is not complete enumeration of causes.

Scientifically, a precise set of initial conditions for the higher layers is impossible to measure or even to specify in the majority of cases. Therefore the higher layers must operate in light of this ineluctable uncertainty. It does not matter whether a conscious intelligence is at work, or blind forces of evolution. There are quantities which are quite real at one level, but which cannot be meaningfully defined or measured at lower levels; for example, blood pressure by the molecular components blood, or the operation of a computer program by study of solid state physics of the transistors, or thought and the firing of neurons.25 In other words, higher levels exhibit organization and behavior quite different from lower layers. This does not imply that causality has broken down; only that causality as a concept is not identifiable with strict determinism. (Of course, if strict determinism were true, Laplace's Demon would rule and everything up to the highest level behavior [evolution of the universe as a whole] could be predicted from knowledge of the fundamental particles.)

There are quite practical reasons for hierarchical organization and the systems approach as well. The most significant may well be the fact that it permits complex dynamic systems to be constructed which are stable. By interconnecting hierarchically large numbers of small subsystems, it is possible to keep the order of each low, and thus be reasonably sure of its stability and ultimately of the interaction of these systems at higher and higher levels. While stability of interacting nonlinear systems is far from well understood, it is known from study of the famous random matrix problem, that stable higher order linear systems are difficult to construct.26

Complementarity of Zubiri's Philosophy and Modern Science

Philosophy and science both seek truth about reality. Throughout its history, philosophy has been influenced by developments in other fields, particularly science and mathematics. This is quite clear in the work of Aristotle, Descartes, and Kant. But a solid working relationship between philosophy and science has proved elusive: either it was difficult to find room for science within the philosophical enterprise, because it covered the same ground, often with contradictory results ("So much the worse for the facts," remarked Hegel), or particular scientific theories and results were wedded to philosophical doctrines, with disastrous consequences later (e.g., Kant). The optimal situation is for scientific knowledge and philosophy to be related in a complementary fashion, rather than vying to answer the same questions.

In his philosophy, Zubiri sought to achieve this type of relationship with science. He was very well acquainted with the state of science and its accomplishments, and knew many of the great scientific figures of the 20th century. But he also knew that philosophy must ultimately deal with questions which are broader and deeper than those science can address, especially since philosophy must establish the foundations upon which all knowledge is erected, including scientific knowledge. As the key scientific events of the 20th century unfolded, Zubiri's extremely broad background and profound insight uniquely positioned him to see how the 19th century paradigm was not simply being altered, but fundamentally destroyed; and that a new paradigm was essential, one with enormous scientific, philosophical, theological, and historical implications. This dovetailed with his broader task, that of crafting a "new synthesis" of human knowledge, rendered necessary in part by the enormous growth of science and the changes it wrought on the intellectual landscape. Though this synthesis task was his primary concern, he had to think through much of the task of creating a new paradigm for science as knowledge about the world, and incorporate it into his philosophical works. In the process, he provided and continues to provide invaluable guidance and insight to those trying to understand the world delivered to us by science; to those seeking the implications of science for other forms of knowledge; and to those doing science and creating new sciences. The balance which he struck, and the comprehensive view of reality emerging from it, can be understood with reference to four key ideas, closely related: (1) limitations to scientific knowledge disclosed in the 20th century, and its deeper meaning; (2) causality and scientific laws; (3) hierarchical nature of reality and openness of the real; and (4) essences and the nature of systems. The new paradigm permits a broad but flexible interface between Zubiri's philosophical synthesis and evolving science, one based upon his key philosophical ideas: the tripartite structure of intelligence,27 essence as the physical structure of reality, and the distinction of the talitative and transcendental orders.28

(1) Limitations to scientific knowledge. Quantum mechanics was regarded as a great scandal at the time of its introduction because of the limitations it placed on scientific knowledge.29 In fact, however, the view displaced is the one which should be regarded as scandalous, because of its many speculative and unverifiable assumptions about human knowledge.30 What the new developments in science tell us is that while unaided reason has hard limits in respect to how far it can penetrate the secrets of the world (in contrast to what classical philosophy and the Continental Rationalists thought), the new language of mathematics used by modern science, though capable of penetrating much farther, also has fundamental limits. The main problem is that while we do directly perceive reality (e.g., the color green is photons as perceived; there are not two realities),31 we do not do so in the absolute, detached sense envisioned by classical science. Zubiri has analyzed this in his theory of sentient intelligence, where he begins by pointing out that the traditional approach to the problems of knowing and reality, an approach at least partly responsible for the shattered views of the 19th century, is radically wrong:

The fact is that an intrinsic priority of knowing over reality or reality over knowing is impossible. Knowing and reality are in their same root strictly and rigorously congeneric. There is no priority of one over the other. And this is true not simply because of de facto conditions of our investigations, but because of an intrinsic and formal condition of the very idea of reality and of knowing. Reality is the formal character—formality—according to which what is apprehended is something in "itself," something de suyo.32

Moreover, modern thought is itself guilty of a great scandal by attempting to relegate fundamental human experiences, such as the perception of color, to the periphery of science and explain it by reduction to other things which are logically dependent upon it. As Lopez Quintas points out:

How can someone ask if the real is deformed through perception if he has no other way of access to reality? On the other hand, to affirm that color is not a reality, one must have previously clarified what type of reality he is talking about, since the problem of reality can be posed at many different levels: that of primary perception and that of what a thing is when it is not perceived.33

Of primary interest is knowledge at the level of reason. Zubiri notes:

But the formality of reality is respectively open in another direction as well. By being pure and simple reality, it is transcendentally open to being a moment of "the" reality. It is, then, open to what we have called "world." Thus to intellectively know what a real thing is in reality is to intellectively know it as a moment of the world. . . . To intellectively know what a color, which we see, is in reality is to intellectively know what it is in the field sense with respect to other notes, e.g. sound. But to intellectively know what that color is in reality as a moment of the world is something different; it is to intellectively know it, for example, as a light wave or a photon.34

The root of the problem is that reality is more complicated than the human mind can understand; and even at the level of reason, it must rely upon multiple explanatory paradigms (science, theology, philosophy, poetry, and so forth) to grasp even a small part of reality. Even with this, reality must be broken down into pieces. There are four related aspects to the problem: (a) not everything has a rational explanation; (b) rational knowledge, including science, is a search not a factum, and therefore always radically incomplete; (c) reality is fundamentally open and not fully capturable by any human formula, and (d) rational knowledge is not the supreme form of intellection.

(a) For the purposes of human knowledge, it is not necessary that everything real have a rational explanation:

We are not dealing with the case that all of the real qua real is necessarily of rational structure; it suffices that something real, to wit, the field real, has this structure. To think that all the real necessarily has its "explanation" not only is an hypothesis, but moreover a falsehood. . . . God is absolute reality; but even in the worldly sense, it is not certain that every reality has a rational explanation. A free act does not. . . .35

Reason, for Zubiri, does not consist in going to reality, but in going from field reality toward worldly reality, toward field reality in depth. If one likes, the field is the system of the sensed real, and the world, the object of reason, is the system of the real as a form of reality. This is important because "world," for Zubiri, is not coextensive with the object of science.36 Other types of rational intellection of the world than science exist, and can tell us other things; indeed, we commonly speak of truth in connection with art and literature, as in Picasso's famous remark, "Art is a lie that reveals the truth."

(b) Moreover, all rational knowledge, including science, is a quest, not an accomplished fact. This is irremediable because it owes to the nature of rational intellection:

The limitation of knowledge is certainly real, but this limitation is something derived from the intrinsic and formal nature of rational intellection, from knowing as such, viz. being inquiring intellection. Only because rational knowledge is formally inquiring . . . must one always seek more and find what was sought as the principle of the next search. Knowledge is limited by being knowledge. An exhaustive knowledge of the real would not be knowledge; it would be intellection of the real without necessity of knowledge. Knowledge is only intellection in search.37

The incompleteness of rational knowledge (and by implication the impossibility of reductionism) is radical, not just an historical inconvenience:

The complex of natural laws would never be able to explain everything present in the thing, because there always exists a margin of individuality and contingency which those laws would never succeed in exhausting.38

(c) Reality is fundamentally open, and therefore not fully capturable in any human formula. This openness is intimately related to transcendentality:

Reality as reality is constitutively open. . . . Reality is not a transcendental concept, nor is it a concept realized transcendentally in each real thing; rather, it is a real and physical moment, i.e., transcendentality is just the openness of the real qua real. . . . The world is open not only because we do not know what things there are or can be in it; it is open above all because no thing, however precise and detailed its constitution, is "the" reality as such.39

The fundamental or constitutive openness of reality means that the search for it is a never-ending quest. Zubiri believes that the development of quantum mechanics in the 20th century has been an example of how our concept of reality has been broadened. The same is true with respect to the concept of person:

An intellection much more difficult than that of quantum physics was needed in order to understand that the real can be real and still not be a thing. Such, for example, is the case of person. Then not only was the field of real things broadened, but that which we might term "the modes of reality" were also broadened. Being a thing is only one of those modes; being a person is another. Thus not only has the catalog of real things been changed, i.e., not only has a reality beyond the field reality been discovered, but the character of reality itself as a measure has changed, because a person is something different from a stone or a tree not just by virtue of his properties, but by his mode of reality . . .40

Elsewhere, Zubiri points out that life, society, and history are also realities which are not objects in the sense of science either.41

(d) Indeed, for Zubiri, the very position of rational knowledge in the "hierarchy" of human knowledge is different. Because of grounding in primordial apprehension, rational knowledge is essentially inferior to it:

Whence it follows that far from being the supreme form of intellection, knowledge is (by being rational actuality of the real, of a logico-historical nature), an intellection which is inferior to the mere intellection of primordial apprehension . . . Knowledge is, I repeat, the successor to primordial apprehension. . . .42

This remains a stumbling block for those who have what amounts to theological designs for science, and for whom renunciation of the ubiquity and universality of scientific explanation would be tantamount to an unconditional surrender, for whom a "Final Theory" of everything is the Holy Grail.43,44

The limitations to scientific and mathematical knowledge, uncovered in the course of science's own development, thus reflect a deeper reality: the underlying structure of the human mind and its ability to know reality through sensible apprehension. It has become clear that our perception of reality is not absolute in the 19th century sense, nor is it the way God perceives the world.45 Science will always have limitations because of the fundamental openness of reality:

This openness is absolute, because however much we find, the search will never exhaust the openness of the world, and this is essential. In contrast to what Leibniz and Kant thought, reason is not totalizing or a totality, but something constitutively open. And this is not due to internal limitations of reason itself, but to the very nature of the real as impressively sensed.46

(2) Causality and scientific laws. Zubiri is keenly aware of the pivotal position of science and scientific laws in any discussion of reality. As discussed earlier, gone is the "classical view" wherein scientific laws were causal laws, and causality was understood as determinism. For him, causality is functionality rather than determinism,47 but functionality remains the broader concept.48 This means that a scientific law expresses a functional relation between quantities of interest, and the nature of that function can vary greatly. Determinism is one type of functionality, as in Newton's second law, F=mx, where the value of x is completely determined once F and m are known; probability is another type of functionality, as in Schrodinger's equation, ih(d¥/dt)=H¥, where ¥ is a probability distribution function. However causality, in its usual acceptation, plays at most a background role; Zubiri's own example is the Universal Gas Law, PV=nRT: no causality is evident in the relationship among pressure, volume, and temperature.49 In the case of biological systems, the functionality can become quite complicated indeed; an example which immediately springs to mind is that of a DNA molecule and its corresponding organism. Other types of functional relations exist, e.g., symmetry as used in subatomic physics; and new ones may be discovered in the future. Moreover, functionality is part of our normal perception of the world:

In classical philosophy a cause is that from which something proceeds by means of a real influence upon the being of the effect. Now, causality is not something given. We never perceive the productive influence of a real thing upon another . . . Our perception never perceives causality, but always does perceive the functionality; in the field of reality we sense reality in its functional moment as a field-nature moment of the impression of reality. We perceive that a thing is real as a function of others, a functionality which can be and is quite varied. Causality is only a type of functionality, and moreover very problematic . . .50

The role of causality is problematic because outside of certain human actions, it is impossible to isolate all of the causes of any event:

Moreover, no substantivity—and this is extremely important—is fully a seat of causality because there is no substantive reality (outside of human reality, and there only in limited dimensions); there is no substantivity which is fully a substance. Therefore, none is fully a cause.51

To see how this view of causality and scientific laws meshes with modern science, it is necessary to ask a critical question: What is related by these functions? That which can be measured. For Zubiri, the concept of "measure" goes far beyond measurement in the quantitative sense understood by science; it is rather an essential part of reason as the highest form of human knowledge. Before tackling the question of measure and science, it is necessary to be clear on just what Zubiri's radically new concept of reason is. Reason is not an organ of absolute evidence (Kant), nor basis of dialectic (Hegel), nor explanation of intellections, nor organization of experience.52 It is what "gives us to think" about things and thus to go beyond what is present at levels of simple reality and logos:

Only as explanation of color is there intellection of electromagnetic waves or photons. The color which gives us to think is what leads us to the electromagnetic wave or to the photon. If it were not for this giving us to think, there would be no intellection of a beyond whatsoever; there would be at most a succession of intellections "on this side . . ."53

But it should not be assumed that only science, through theoretical constructs, can achieve this intellection:

The beyond is not just a theoretical concept, as are the wave and the photon, for example. The beyond can also be what forges a novel; we would not create the novel if the real did not give us to think. The same could be said of poetry: the poet poetizes because things give him to think. And that which he thinks of them is his poetry. That what is intellectively known in this manner is a reality which is theoretically conceptualized, or a reality in fiction, or a poetic reality, and does not change the essence of intellection as reason. A metaphor is one type of reasoning about things, among others. What is intellectively known of the beyond is purely and simply the intellection of what the things "on this side," upon being intellectively known, give us to think. Therefore intellection of the beyond is reason or explanation, is intellection of the real in depth.54

The notion of measure in connection with reason can now be understood. Every thinking intellection, for Zubiri, is based upon a principle of intellection. This principle he terms a "fundament-reality."55 It is in accordance with the fundament-reality that a thinking intellection gauges the reality of what is present to it, or as Zubiri says, measures it. He takes as an example the conceptual shift required by quantum mechanics: in our most elementary field experience, we term material things "bodies." It was always assumed that things "beyond" the field were also bodies. Quantum mechanics disclosed that the real beyond the field is not always a body:

Elementary particles, in fact, are not corpuscles . . . but another class of material things. Borne along by the field intellection of things, we were disposed to intellectively know the things beyond the field as bodies, different perhaps, but when all was said and done, still bodies. The measure of the real was undertaken with a determinate metric: "body." Now, the progress toward reality has opened up to us other real material things which are not bodies.56

Our canon of reality, in this sense, was thus enlarged. This canon, however inadequate, is nonetheless essential because it imparts a direction to our searching; in the case cited, it was only by seeking bodies that we encountered something new. Reason, indeed, is intellectus quaerens, a quest or search. Reason therefore has a certain character of provisionality:

The scientific method is "a" way of access to in-depth reality, but not every way of access is a scientific method. . . . there is no implication that we will in fact actually reach this true encounter [with reality]; it may perhaps not always be possible. Science is not, as Kant thought, a Faktum, but an effort, not just with respect to its content, but also and above all with respect to the very possibilities of its existence—something completely different than the conditions of possibility of a science already achieved, such as the science about which Kant spoke. Science, in accordance with the three constitutive moments of rational intellection, is essentially a problematic knowledge, viz. a knowledge which seeks to take on the form of experimental facts, of a precise method of experimentation, or of fundamentation of verifiable truths.57

Thus measurement, as understood in science, is a subclass of the more general type of measurement which constitutes part of reason as thinking intellection. In fact, measurement in science goes on at several levels: at the lowest, it is comparison of something with a fixed standard, e.g., a meter stick, which forms part of the canon of measurable quantities and standards (length, time, voltage, etc.). At an intermediate level, measurement is comparison of what is observed with the canon of what is already known to exist, e.g. species of plants or animals, or subatomic particles. But at the highest level—a level virtually unrecognized prior to the 20th century—it is exploration of in-depth reality based on the canon of types or classes reality known at the time, e.g., material bodies. A change in the canon at this level generally entails a paradigm shift in Kuhn's sense:

Reason is always subject to possible canonic "renovations" or "repairs," which by virtue of being so are rational renovations. This renovation clearly concerns the content of what is presented in the canon . . . [It] not only remakes the content of what is presented as real, but also the very direction of all subsequent search, or all subsequent reason; whence it is that the direction of reason is always provisional. Provisional does not mean that it is false . . . Rather, it means that even if true, it is a truth which by its very nature will not necessarily be derogated, but superseded.58

Scientific theories and laws are thus a way of measuring reality, but not the only way nor a comprehensive way.

(3) Hierarchical nature of reality: openness of the real. Science has disclosed to us the essentially hierarchical nature of the real, as well as its dynamical character at all levels. This implies mutual relationships among what we term "things" at each level, things which tend to be defined through their dynamic relationships with other things at the same hierarchical level, as well as their contribution to higher levels. At the deepest level, quantum mechanics and the Aspect experiment have revealed how the entire universe is, in a real sense, linked. Science, slowly and painfully, attempts to determine the nature of these relationships; but the richness and depth of nature and its interrelationships will likely always far exceed the capabilities of the human mind. The causal nexus is too complicated to fathom; therefore we understand things through functional relationships, usually expressed mathematically. Moreover, as we now know from chaos theory, many systems have behavior so complex that no mathematical model will ever be able to predict them; they are, in this sense, their own fastest computer.59 Such, for example, is likely the case with economic systems, and biological systems with respect to evolution. All of this is in marked contrast to the more static traditional philosophical concept of things as discrete substances, somewhat monolithically based on essence as the correlate of a definition, assumed knowable in some ultimate sense.

Zubiri's philosophy, once again, is congruent with the new world outlook emerging from science through his notions of the respective nature of all reality, and its correlate, openness.60 Respectivity implies the type of interdependence which we now understand through science as characterizing the physical world, and openness implies the type of radical incompleteness which has emerged in the scientific picture of the world.

All knowledge, by virtue of being an intellection with a system of possibilities freely constructed from a system of reference, is an open knowledge, not just in fact and because of human, social, and historical limitations. Rather, it is open qua knowledge through intrinsic necessity, to wit, through being intellection as sketch. And this is a moment which is formally constitutive of rational intellection as such.61

Hierarchical organization of reality is suggested by its complexity:

And this dynamic unity is the dynamic unity of the layers or degrees of reality. I say "dynamic unity" because it does not seem to me that reality is a question of gradations (i.e., that there are realities more real than others), but that it is a true dynamic unity in which each higher reality, in the order of reality, is mounted upon the substratum of a reality of lower order.62

In a typical example of the essentially hierarchical nature of reality, Zubiri considers the emergence of new, irreducible properties in a chemical compound, which represents a transformation:

Hydrochloric acid, like all other realities of the world, is a structural system. And if the hydrochloric acid is a new body, it is not because the substances which resulted in it are maintained either actually or virtually; but because these substances have given way to systematically new properties, which are not distributable among the elements which gave rise to the hydrochloric acid. . . . Systematic properties do not reduce to an addition and to a merely additive complication of elemental properties, but are new properties.63

The relationship or congruence with science is now clear: reality, as disclosed to us by science, is essentially hierarchical. There is no ability to understand everything about it from one level; multiple hierarchical levels are required.64 No thing exists or is understood by itself, but in relation to others, dynamically. In a remarkable passage, Zubiri points out the connection between respectivity and the essentially hierarchical nature of reality:

Here one starts from an initial and radical respectivity, in virtue of which each substantivity is in re essentially and constitutively respective. Here we are not dealing with an order of cause but with something different: a fundamentation of causality. . . . and I say that the various dynamisms . . . are founded some upon others. The most elemental are therefore the basic dynamisms. [Though] the others are in no way reducible to the basic ones. . . . they cannot be what they are unless founded upon the elemental and basic dynamisms. This is readily apparent in the problem of a particular type of dynamism, variation and change . . .65

The dar de sí ultimately relates to the structural complexity, or level of organization, of realities:

In variation there is the maximum of change and minimum of becoming. Insofar as one ascends the scale of realities, there is more becoming and less change. . . . The richer the substantivity, the more it gives of itself and the less it changes.66

Things are not just collections of characteristics or notes, in some static sense; rather, these notes have an essential dynamic nature, the dar de sí, or giving from itself. This is part of the formal structure of things, their active moment, which springs from their being de suyo.67

(4) Essences and the nature of systems. Essence is one of the most profound subjects of human thought, and has exercised many of the greatest minds from antiquity to the present day. The central place of essence in human speculation inevitably means that in an age of science, its nature and relationship to the scientifically revealed world will become critically important. Do scientific discoveries about the nature of things bear on essence?

Zubiri greatly broadened and deepened our understanding of essence, both in the logical as well as the physical sense. He reviews old concepts of essence, and rejects them all as insufficient, before proposing his own, founded upon the notion of system:

The basic, constitutive system of all the notes which are necessary and sufficient for a substantive reality to be what it is, is precisely what I have called essence. It is the primary, coherential, unity.68

For Zubiri, it is the interrelationship of the notes making up essence which is important; each constitutive note is present by virtue of its place in constituting the whole. The notes are mutually dependent, and often lose their individual identity in the constituted system.69 Every reality is thus a systematic unity.70 This general discussion is in agreement with the modern scientific concept of things as dynamic systems, in which the interrelationship of the components makes the thing what it is, with its own behavior, different than that of its constituents and often obscuring them.

In light of Zubiri's discussion, it is apparent that old concepts of essence are not congruent with science because they are what I term "flat," i.e., they assume that there is an absolute character of everything that can be captured by some act of the mind, usually unaided, on the basis of which we then "know" the thing. The primary example, of course, is the classical definition in terms of genus and species, with the example, "man is a rational animal," though Hegel and Husserl immediately come to mind as well. Zubiri correctly points out that all such concepts of essence are inadequate because they do not capture its key physical property, that of structure, the de suyo, from which emerge all of its properties or notes, including its dynamics, the dar de sí. This is more along the lines of Aristotle's to ti en einai, but without the logical connotations which it ultimately assumed. Clearly, behavior such as we now understand, from biological evolution to chaos, is of an entirely different order than that envisioned by the creators of the old concepts of essence; and it involves layers of structure which point to a far richer and more complex reality than those concepts are capable of expressing. Indeed, it is unclear that essences can be adequately expressed at all in normal language.

The probing activity of science, through sketching of possibilities and use of experiment, may be the principal route to knowledge of essences, even though essence appears logically in primordial apprehension. Zubiri's concept of essence is thus much more profound, but also much more difficult to achieve, than earlier conceptions of it. He notes:

Essence is not to be sought in the metaphysical analysis of the predicates which are attributed to the thing, but rather, on the contrary, in the analysis of its real structures, of its notes, and of the function which these fulfill in the constitutional system of its individual substantivity. . . . It is the essence as "physical" moment of the real thing.71

This is true with respect to inanimate physical objects as well as biological organisms, where structure ultimately depends upon genotype:

The primary structure of a thing is its "constitution." It is precisely because of this that I decided to give philosophical rank to this concept. Constitution thus understood is of a "physical" and not a logical character. . . . It is necessary to amplify the concept [of constitution] and include in it physical characteristics which are specific (the genotype).72

With respect to Zubiri's concept of essence and modern science, there are three key points: (a) the increasing focus on systems, hierarchically organized, as the object of scientific inquiry; (b) recognition of the exceeding complexity of nature and the complexity of behavior which things in it can exhibit; and (c) the recognition that there is no need to postulate ultimate realities "beyond" what is observed.

(a) Zubiri's notion of essence concentrates on its system aspect, which is increasingly the focus of science as well, in part as a result of the recognition, at least in practical terms, of the impossibility of reductionism, and the recognition that knowledge about reality must proceed in different ways and with different methods and assumptions at different hierarchical levels. For example, the biologist or evolutionist use different assumptions and different boundary conditions than the particle physicist. Moreover, things higher in the hierarchy may possess entirely new properties, and because of the dynamics of the new composite systems, the properties of their component subsystems in isolation may fade or become invisible; as Zubiri has pointed out:

Compound substances may also possess certain properties as a system of a totally different kind from the systematic properties of its elements, and may be of the type which we have called functional combinations. There are compositions in which the compound, because it possesses substantivity, is equally with its components taken in isolation, a substance; this is the case with any chemical substance. However, there are other compounds, such as living beings, in which the characteristic and differential moment of their substantivity is of a purely functional type . . .73

(b) There is also an implicit recognition of the great complexity of reality, built up of systems of systems of systems . . . which does not permit anything to be captured, in isolation, in a curt formula or vision.74 Indeed, as we have learned over the past few decades, even simple dynamical systems can give rise to extremely complex behavior. Our awareness of the structural and behavioral complexity of biological organisms and higher levels of organization, such as ecosystems, is steadily increasing. Zubiri's notion of essence is quite capable of dealing with this situation; earlier concepts, such as the correlate of a definition in terms of genus and species, are not.

(c) Finally, science does not look for some reality beyond the systems it examines; they are the reality at each level. For example, a society is a complex system with certain characteristics, some of which can be modeled mathematically. There is no "real" society lurking behind the system and giving rise to the observed properties. On the philosophical side, Zubiri has said the same:

This substantivity is nothing hidden, or still less, something situated "behind" the system of constitutional notes or "beneath" it; rather, it is the system itself as such. Neither, for this same reason, is essence something which is found beneath the substantivity; it is, rather, an internal and formal moment of the system itself as such.75

Zubiri's concept of essence, then, is one which makes sense from both a philosophical and a scientific viewpoint. Science searches for the ultimate structural principles of things, and has already abolished the Greek distinction between natural things and man-made things. Science, through its method,76 tells us about the world, about these structural principles and their dyanamics, these systems, which knowledge is grounded in logos and ultimately in primordial apprehension. The task of the philosopher is not to try an end-run around science, and short-circuit the investigation of reality by propounding "true" essences obtained unaided through sheer intuition; rather, it is to understand how all of the diverse forms of knowledge fit together in an integrated whole, based in reality. If one likes, it is to deal with reality in the transcendental order, as opposed to the talitative order (bearing in mind that these two are not disjoint). There is no problem of two types of knowledge of reality, one through philosophical essence and another through scientific "essence," disconnected from it and based on entirely different principles, possibly leading to some new "dual truth" crisis such as arose in the Middle Ages.


The four principal ideas discussed above are summarized in Table 1, which includes the 19th century view, the contemporary scientific situation, and Zubiri's resolution of the matter. The resolution indicated is not dependent upon any particular scientific theory, but upon the nature of science as a rational human enterprise, with roots ultimately in the primordial apprehension of reality.

Application to Apologetics

No civilization can sustain an intellectual force as powerful as modern science, but lack a comprehensive vision of how that force meshes with its other cultural values and its understanding of reality. The inevitable catastrophic result would be domination by science and an associated world-view, with values being added on the basis of some fashionable ideology. It can be argued that we are perilously close to this situation at present. The analogous occurrence in the Middle Ages, when Aristotelian thought was reintroduced into Europe, is well-known.77 Domination of knowledge by science, which appears to be growing steadily in our society, has had many undesirable effects. Among them are erosion of belief in God and Divine Revelation, substitution of "scientifically possible" for "morally acceptable," and the rise of pseudo-scientific ideologies such as communism. Much of this is operational, affecting practical attitudes, rather than explicit rejection; but it is real nonetheless, as witnessed by the casual attitude toward marriage, divorce, sexuality, and abortion even among many nominal Catholics.

Therefore the problem must be met head-on; the question of science and its limits has to be addressed from the standpoint of a global understanding of all knowledge. When someone asks the naïve question, "Hasn't science disproved religion?," the more sophisticated, "Doesn't the insignificant place of the earth in the incredibly huge, violent 15 billion year-old universe show that the Bible is not trustworthy?," or the confrontational, "Just tell me what science can't ever explain and theology can!," the answer cannot be ad hoc, but must flow from a comprehensive vision ultimately rooted in the questioner's own fundamental experience of the world and our knowledge of it. This in turn implies the need for a grand synthesis, one capable of integrating new knowledge as well as making sense of present knowledge and Divine Revelation. Such a synthesis must be founded in our most direct and basic experiences of reality as human beings (rather than upon lengthy chains of reasoning, subjectivism, or even science); and must show how all branches of knowledge, all experience, and all limitations associated with our finiteness as creatures fit into the picture. Zubiri was keenly aware of the need for this synthesis, of course, and told me so in a conversation I had with him outside the Banco Urquijo in Madrid in 1982.

Zubiri did not base his philosophy on the state of science at some moment in time; rather, he created a broad but flexible interface with science and scientific concepts, and developed a comprehensive explanation of how the reality delivered to us through science integrates with other knowledge of reality. This he did with respect to the following points:

1. The nature of human knowledge vis-a-vis basic experience. Zubiri establishes that there are some truths, such as the structure of the intelligence, which are prior to science and not accessible to it, and which ultimately ground science and all other rational knowledge.

2. How knowledge in fields outside of what we today call "science," such as literature and theology, fits into the comprehensive scheme of human knowledge. Zubiri demonstrates how such sources of rational knowledge can also tell us about the world, in ways which science cannot, thus establishing a framework for knowledge such as literature, poetry, and theology, which were effectively frozen out of the 19th century world view.

3. The limitations to any form of rational knowledge, including science. Zubiri has constructed a system which acknowledges the ongoing contribution of science to our canon of knowledge; one which is in continual dialogue with science, but not slavishly dependent upon particular theories. In particular, it readily accommodates the key ideas of and the limitations to science disclosed in the 20th century: the radical indeterminism of nature, the non-corporeal structure of matter, the impossibility of reductionism, the hierarchical nature of reality, and the central place of systems in the canon of reality. At the same time, Zubiri recognizes the changing and evolving nature of science as a font of rational knowledge, one which, like others, is provisional and directional.

4. Complementarity between scientific knowledge and metaphysical knowledge of reality. Zubiri's key philosophical concepts, such as essence, are congruent with but not dependent upon knowledge gleaned from science; and make sense of both science as a human activity seeking truth about reality, and of a critical analysis of our intellective processes. This forecloses the possibility of a "dual truth" paradox and allows for new concepts of reality and new paradigm shifts.

5. Nature and priority of philosophical knowledge. Zubiri does not turn philosophy into a branch of science or vice versa. Rather, he takes an Olympian perspective on the whole of human knowledge and experience, recognizing that while science will never take its direction from philosophy, and that our ability to understand the world "beyond" our perception will rest in large measure upon scientific discoveries and theories, the understanding of science as an enterprise and of scientific results ultimately depends upon the structure of human intelligence as sentient.

With this, of course, the task of refounding apologetics to address the new world order of the 21st century is only begun, though it perhaps represents the most important step. Science is, in many ways, the lingua franca of the world today with respect to knowledge; and if that world of diverse cultures is to be converted, it will have to be done in part by showing how the Catholic position not only does no violence to the essential aspects of science, but indeed facilitates understanding of them in the total context of human life more so than can any other religion or system. In the final analysis, this is because truth is one and therefore science, properly understood, will accord with the truths of faith and confirm them.

Thomas B. Fowler, Sc. D. is Professor of Math and Science at Christendom College and translator of Nature, History, God by Xavier Zubiri (published by University Press of America; available through Christendom Press).


1 Paper presented at the Congreso Internacional Xavier Zubiri, Madrid, July 1993, with the title, El gran cambio de paradigma: Xavier Zubiri y la revolucion científica, 1890-


2 Nature, History, God, tr. by Thomas B. Fowler (Washington, DC: University Press of America, 1981), p. 51. Hereafter, NHD.

3 In retrospect, it is clear that even under the suppositions of Newtonian physics, the reductionist goal was hopelessly unrealizable from any practical standpoint and therefore unverifiable. Brillouin (Scientific Uncertainty and Information [New York: Academic Press, 1964], p. 24) has pointed out that a motion of 1 gram of matter by 1 cm on a nearby star (e.g., Sirius) would change the gravitational field on the earth by about 10-100—small but enough to make it impossible to compute the motions of particles in an ideal gas for more than 10-6 second.

4 NHD, pp. 253-254.

5 NHD, p. 266.

6 J. S. Bell, Speakable and Unspeakable in Quantum Mechanics (Cambridge: Cambridge University Press, 1987), pp. 1-40.

7 P. C. Davies, J. Gribben, The Matter Myth (New York: Simon and Schuster, 1992), p. 224.

8 P. C. Davies, J. R. Brown, The Ghost in the Atom (Cambridge: Cambridge University Press, 1986), p. 17ff.

9 NHD, p. 265.

10 Gleick, Chaos (New York: Viking, 1987).

11 T. Fowler, "Application of Stochastic Control Techniques to Chaotic Nonlinear Systems," IEEE Trans. Automatic Control, 34: 201-205 (February, 1989).

12 S. Krashner, ed., The Ubiquity of Chaos (Washington, DC: American Association for the Advancement of Science, 1990).

13 M. Schroeder, Fractals, Chaos, Power Laws (New York: Freeman, 1991), p. 25.

14 The nature of chaos is sometimes misunderstood. Technically, if initial conditions were able to be specified with sufficient precision—which might mean dozens of decimal places—the chaotic systems could be made predictable for any desired time into the future, though their behavior would remain extremely erratic by normal standards. In fact, however, the necessary degree of precision is chimerical because of quantum mechanical limitations, random noise, and limitations imposed by the atomic structure of the measuring instruments. Philosophically, one could go on maintaining that any arbitrary degree of precision in measurements has meaning; scientifically, in terms of what can physically be measured, it does not.

15 NHD, p. 252.

16 NHD, p. 253.

17 NHD, p. 256.

18 Estructura dinámica de la realidad (Madrid: Alianza editorial/Fundacíon Xavier Zubiri, 1989), p. 99. Hereafter, ED.

19 Inteligencia y logos (Madrid: Sociedad de Estudios y Publicacions/Alianza editorial, 1982), pp. 138-139 (Spanish edition). Openness in Zubiri's philosophy refers to the radical incompleteness, as it were, of things as actualized in the human intellect, the inability to treat them as completely isolatable.

20 ED, p. 64.

21 Cf. T. Fowler, "The Genetic Code: Nature's OSI Protocol?," J. Theo. Biology, submitted.

22 ED, pp. 90, 97.

23 ED, pp. 84-85.

24 ED, p. 90.

25 D. Hofstader, Godel, Escher, Bach (New York: Random House, 1980).

26 R. McMurtrie, "Determinants of Stability of Large Randomly Connected Systems," J. Theo. Biology, 50: 1-11 (1975).

27 Zubiri analyzes human intelligence in three modes or phases: (1) Primordial apprehension of reality (or basic, direct installation in reality); (2) Logos (explanation of what something is vis-a-vis other things, or what the real of primordial apprehension is in reality); (3) Reason (or ratio, methodological explanation of what things are and why they are, as is done in science, for example). This process, whose three phases unfold logically if not chronologically in sequence, is mediated by what Zubiri calls the "field" of reality. The reality field concept is loosely based on the field concept from physics, such as the gravitational field, where a body exists "by itself," so to speak; but also by virtue of its existence, creates a field around itself through which it interacts with other bodies. Thus in the field of reality, a thing has an individual moment and a field moment. The individual moment Zubiri refers to as the thing existing "by itself" or "of itself"; de suyo is the technical term he employs, derived from the concept of ex se in canon law. Roughly speaking, primordial apprehension installs us in reality and delivers things to us in their individual and field moments; logos deals with things in the field, how they relate to each other; and reason tells us what they are in the sense of methodological explanation.

28 For Zubiri, the talitative order (from the Spanish talidad, meaning suchness), refers to the one of the orders which are actualized in the impression of reality, that which refers to the suchness of what is actualized. This is the primary object of science. The other order, transcendentality, is the object of metaphysics.

29 NHD, p. 253.

30 John Templeton, Who's Who in Theology and Science, 1992 edition (Framingham: Winthrop Publishing Company, 1992), Introduction, p. vii.

31 Inteligencia sentiente (Madrid: Sociedad de Estudios y Publicaciones/Alianza editorial, 1980), p. 186 (Spanish edition).

32 Inteligencia sentiente, p. 10 (Spanish edition).

33 Lopez Quintas, op. cit., p. 254.

34 Inteligencia sentiente, pp. 269-270.

35 Inteligencia y razon (Madrid: Sociedad de Estudios y Publicaciones/Alianza editorial, 1983), p. 284. Hereafter, IR.

36 IR, p. 171.

37 IR, p. 262.

38 On Essence, 130 Eng./106 sp.

39 IR, pp. 20-21.

40 IR, pp. 56-57.

41 IR, p. 178.

42 IR, p. 316.

43 Steven Weinberg, Dreams of a Final Theory (New York: Pantheon, 1992).

44 J. D. Barrow, Theories of Everything: The Quest for Ultimate Explanation (Oxford: Oxford University Press, 1991).

45 NHD, p. 302 (Sp. ed.).

46 IR, p. 103.

47 Technically, functionality means the formal unity of two moments of the formality of the real: the individual moment and the field moment. IR, pp. 229-230.

48 IR, p. 237.

49 IR, p. 237.

50 Inteligencia y logos, p. 40.

51 ED, p. 90.

52 IR, pp. 68-69.

53 IR, p. 43.

54 IR, pp. 43-44.

55 IR, pp. 47-50.

56 IR, p. 56.

57 IR, pp. 172-173.

58 IR, pp. 62-63.

59 R. Jensen, "Classical Chaos," American Scientist 75: 168-181 (March-April, 1987).

60 Much of Zubiri's analysis of this question deals with reality prior to the world "beyond" which is the subject of reason. But as Diego Gracia has pointed out, "What Zubiri analyzed [in On Essence] was the formal structure of reality, the structure of reality as formality, i.e., reality qua actualized in apprehension. To be sure, this is also its structure beyond apprehension, since the de suyo remains the same in and beyond apprehension; but his analysis starts from apprehension in order to go toward the beyond . . ." (Voluntad de verdad (Barcelona: labor Universitaria, 1986), pp. 171-172. Thus it makes perfect sense to speak of these concepts, and later on essence, in contexts referring to what is "beyond" apprehension.

61 IR, p. 222.

62 ED, p. 326.

63 ED, pp. 137-140.

64 ED, p. 96.

65 ED, p. 103.

66 ED, p. 104.

67 ED, p. 61.

68 ED, p. 35.

69 On Essence, p. 144 Sp., Lopez Quintas, op. cit., p. 225.

70 On Essence, p. 266 Sp.

71 On Essence, 188 Eng., 177 Sp.

72 On Essence, 137 [new edition].

73 On Essence, 171 Eng., 156-157 Sp.

74 Cf. remarks on Hegel, On Essence, 76 Eng., 44-46 Sp.

75 On Essence, 200 Eng., 191 Sp.

76 IR, pp. 242-243.

77 E. Gilson, Reason and Revelation in the Middle Ages (New York: Scribner's, 1938).

This article was taken from the Summer 1994 issue of "Faith & Reason". Subscriptions available from Christendom Press, 2101 Shenandoah Shores Road, Ft. Royal, VA 22630, 703-636-2900, Fax 703-636-1655. Published quarterly at $20.00 per year.