Philosophers ask many questions about many things, including their own discipline. One of the important questions about the discipline of philosophy is this: Is philosophy a reliable means of knowledge?

The question whether philosophy can amount to knowledge becomes particularly acute when it is considered in the contrast with the hard sciences. The history of philosophy is littered with age-old problems that remain unsettled. Moral philosophers today still disagree about the Euthyphro problem (Is the Good good because the gods will it, or do the gods will the Good because it is good?) Philosophers of mind disagree about whether thought requires a brain. But mathematicians no longer argue amongst themselves ocer the proof for Fermat’s last theorem or Turing’s answer to the halting problem. Physicists after Einstein do not engage in internecine debates about whether space and time are absolute. Biologists do not in an uproar over the occurrence of photosynthesis or the Krebs cycle.

It would seem that the empirical sciences possess the ability to resolve their problems, while philosophers do not. Is metaphysics merely opinion masquerading as knowledge, a merely poetic point of view on the universe (and sometimes bad poetry at that)? To put the question more pointedly, is metaphysics little more than the chronology of the unanswerable questions philosophers ask—of historical interest, but little more, like the bathing habits of the Romans? Or does it, like Euclid’s geometry and the sieve of Eratosthenes, step outside historical circumstance to touch on Truth?

In this article, we will focus our attention on the philosophy of being, metaphysics. And our question will be whether philosophers have anything reliable to say about reality.

Metaphysics as a Science 

First, we need to define what metaphysics is, and place it among the other branches of knowledge.

Metaphysics is a science—at least, that is its aspiration. It aims at an explanation of the real world: it does not aim to excite the imagination. That Lucretius is a better poet than Plotinus has no bearing whatsoever on who is the better guide to philosophy.

Common sense is a form of knowledge that aims at meeting the practical demands of life. We say one “knows” how to play an instrument or speak a language. These skills are genuine forms of knowledge, but they bear on how to do things. Engineering is more rarefied still, but its objective is the production of things like bridges or transistors. Metaphysics is a pure science.

Pure sciences aim at knowledge for its own sake – full, complete, exhaustive explanations. They are incomplete until they achieve a total explanation of things as they are in themselves and in their relations to other things.

Science begins in wonder – why do the stars move? Why do animals grow? But it refuses to languish there. Scientists seeks the “aha!” moment, the key insight, that could explain why the world is as it is, or why things act and interact as they do. These insights are articulated in the form of an abstract theory. They do not merely describe the world or predict what might happen next. They posit a higher, theoretical frame that makes sense of observations, descriptions, and predictions. Galileo knew the approximate rate at which objects fell. He proffered the descriptive definition of acceleration as the change in velocity over time. But it was Newton who hazarded an explanation as to why this occurs, by defining acceleration purely in relation to mass and force.

And finally, the empirical sciences must verify that theory in experience. It is not enough to have a possible explanation. That explanation must account for all the relevant data, and it must do so better than any alternative account.

Pure science refers to knowledge i) that is sought purely for its own sake, ii) that aims at things as they are in themselves and in their objective relations to other things, iii) that is expressed in an abstract theoretical framework, and iv) is verified in experience.

What is metaphysics about? 

All particular questions are addressed by some particular science. Philosophy will not tell us the nature of the stars or of life. Any particular question about the nature of something falls to some particular department of science.

But if all particular answers belong to a particular science, and metaphysics is not a particular science, what remains for metaphysics to explain?

Physics inquires into fundamental particles and change, biology into the emergence and behavior of living things, economics into the productive activity of a society. Metaphysics inquires into the entire business of scientific explanation, and into the world which is so explained. It does not reflect directly on things. Metaphysics contemplates the activity and nature of scientific inquiry, and the world whose nature is thereby revealed.

Metaphysics aspires to be a science. As a science, it must have data into which it can inquire. This data is the history and practice of science. But science must also have a theoretical framework. If chemistry has the periodic table of elements, what is the theoretical framework of metaphysics?

In his work Insight, the Canadian Jesuit Bernard Lonergan proposed the following picture:

Mental operation	Progression	Metaphysical Element
Experience	Observation -> measurement -> scientific description	Matter
Understanding	Insight (Eureka!) -> definition, formulation in general theory	Form
Judgment	Determine conditions -> weigh evidence -> affirmation	Act

This picture is inspired particularly by Aristotle and St. Thomas Aquinas.

Let us consider each level, beginning with the central level of understanding.

Understanding. Understanding begins in the “aha!” moment, the illumination of the inquiring mind. Newton narrates the story of sitting under a tree and watching an apple fall, when the idea that all bodies may be subject to an attractive force came to him. The initial insight is then formulated in terms of an abstract theory. In Newton’s case, this is classical mechanics.

Experience. Scientific inquiry always begins in some experience that inspires the scientist to wonder. For instance, “why do the planets move as they do?” Measurements are made and tabulated. But the answer eludes us so long as we merely see what is there. We need to understand, to formulate a general theory (on the level of understanding) that is correct (the level of judgement).

Yet a correct theory is not enough for a full explanation of the world. Theoretical understanding and general laws disclose the nature of a star and its range of activities, but it does not tell us how many stars there are or their current state. Thus, the particularities that obtain at points in space and time are ascertained by observation constitute the material component of the universe.

Judgement. An unverified theory is merely a hypothesis. It is an idea about what could be. It is a possible explanation. In order to be certain that we have understood what really is, the scientist must be sure that it adequately addresses all the relevant questions on all the relevant data. There can be no more adequate explanation waiting in the wings.

Newton’s classical mechanics is an excellent example. Newton’s theory asserted that space is absolute and infinite. However, advances in physics overturned this hypothesis as more comprehensive theories (Einstein’s relativity) better explained the data.

We do not have to understand physics to understand the general point. What metaphysics seeks to explain is not some particular scientific question (such as, “What is the nature of time?”). Rather, its basis is the fixed structure of scientific explanation: experience, understanding, and judgement. From this basis, it moves to a world with a corresponding three-fold structure.

The notions of matter, form, and act are only general terms, the particulars being filled in by the sciences. What particular things are and how they act and interact with each other is a question for particular sciences. Metaphysics outlines the structure of the universe and its relation to our knowledge.

Objections and Replies 

We began with the problem that history is filled with different metaphysical systems. Are we simply asserting that one conception is right, amplifying the disorganized clamor with one more opinion?

To answer this objection, we need to distinguish two questions: is the view of metaphysics we have outlined certain? And second, if we can have certainty as to metaphysics, why is the discipline of metaphysics in such disarray?

The trouble with rejecting this metaphysics is that in the very act of denial, we presuppose its truth. You must have read the argument, operating on the level of experience. You must have understood what was said not because you imagined me saying it, but because you grasped the meaning, articulated it in your own words, and drew out its implications. That is to say, you must understand the issue. And finally, you must show that you not only grasp the meaning, but that you can critically assess whether it is true or false. To engage in intelligent disputation, you must make use the very mental structure and method whose veracity you deny.

Once you enter into rational discourse, therefore, you commit to the idea that experience, understanding, and judgement are each essential to knowing the truth. And our desire to know encompasses all that is – the entire ambit of being is partitioned into what we already know, and what remains to be known. If one asserts the existence of what cannot, in principle, be understood, one speaks nonsense.

Thus, we can have certainty in a methodically grounded form of metaphysics, because it follows from the universal structure of scientific inquiry and rigorous explanation. The stunning success of the modern sciences only provides further evidence that the universe is really intelligible, and that if we do not yet have a final grasp of the universe, at least the advance of science heads in that direction.

That is not to say that metaphysicians never disagree. Any system of metaphysics must not only be able to explain why it is right; it must also be able to convincingly explain why other systems go wrong. For if metaphysics deals only indirectly with the content of the sciences, it cannot help but deal directly with metaphysicians.

It is easy to think, in a survey course, that history is littered with mutually exclusive metaphysical systems. But that is an oversimplification; in fact there is a great deal of common ground. All forms of metaphysics use the cognitional structure of experience, understanding, and judgement. As a result, differences in metaphysics result either from a gap, an incompleteness, or a distortion.

The major distortion involves a direct rejection of the ground and purpose of metaphysics. It is distinguished from the minor distortions, because it attempts metaphysics while mistaking what metaphysics is. Its primary form is the denial that metaphysics is based on scientific explanation.

For example, someone might assert that metaphysics does not reflect on a scientific understanding of the world, but of the world of ordinary experience. Thus, the “reality” of the tree is not what is conceived and verified by the plant biologist, but a vague combination of the sense of object-permanence we develop as infants, the sensible patterns we associate with words as toddlers, and the casual familiarity of everyday life.

Or again, some might argue that metaphysics appeals not to scientific understanding and critical judgement, but to our aesthetic sense. On this view metaphysics is judged by imaginative creativity or aesthetic appeal. Metaphysics degenerates into whimsy, which explains nothing however much it entertains at dinner parties.

Why would metaphysical thinkers mistake the nature of metaphysics? Because they are not merely rational, they are rational, social animals. In addition to the labor of thought, they must get by in daily life, many have families to care for, and like any other person they not merely want to get through life, they want to enjoy it. As a result, their mental life involves not only scientific thought, but practical common sense and aesthetic enjoyment and reflection. The mind is multi-form, and its shifts go mostly unnoticed.

The interference is a result of not recognizing when the pattern and purpose of their thinking shifts from explanation (things in themselves or their objective relations to each other) to something else (usually things in relation to our senses, our tastes, or our purposes). In a Socratic vein, we might say that the major mistake metaphysicians make in metaphysics is not understanding themselves.

We can identify other ways in which metaphysicians go wrong. Often, they confuse one part of the threefold structure of knowledge with another part, or with the whole. Most commonly, perceiving is confused with understanding.

Two short examples will suffice. Plato was certainly on the right track when he argued that the senses do not bring knowledge; true understanding is conceived within the mind in response to inquiry. However, much of the Platonic tradition regarded knowing as a kind of looking with the mind’s eye. Knowing is not the perfection of the knower, but a relation in which the knower beholds the known.

This notion that the knower and the known must be different, and that the knower’s knowledge depends on the extrinsic known object, led to the heresy of subordinationism in the early Church–the notion that the Logos must be lesser than the Father. It generates an insoluble paradox that God is both self-sufficient and infinite, yet depends upon the world for the fullness of his knowledge.

A more modern example is British empiricism, which holds that knowing is perceiving with the senses (or internal introspection). All knowledge comes from the senses not – as with Aristotle – because there must be something to stimulate wonder, but because knowing is simply a repetition of patterns of sensations. The idea of light is not what is understood by physics of light, but by recalling experiences of light.

Conclusion 

If scientific understanding provides the invariant structure for metaphysics, it also poses the question of the ultimate. Being is that which would be known if everything were fully understood. But can science yield such a total explanation?

Put differently, metaphysics gives us the understanding we need to ask the question: is this physical universe all that exists? Or must there be something more? Are we, as human beings, reducible to the laws of physics, or are we spirits? In order to explain the limited, imperfect, changing, partially intelligible world, must we posit an unlimited, perfect, unchanging and fully intelligent cause? May we merely hope that God exists, or may we know?

A fuller treatment than I have given here is called for, if this question is to be answered. (And I commend to you Bernard Lonergan’s Insight.) But we have shed some light on the foundation: our desire to know aims at a knowing that is complete, that leaves no questions unresolved.

Any knowledge that is grounded on experience and judgement will always be partial. For experience limits our attention now to this, and now to that. And the need for judgement follows from an understanding that is limited (since it leaves further questions to be asked and answered). Again, we need judgement when what is grasped in understanding is merely possible.

But total knowledge must grasp the necessary. It grasps what both cannot be otherwise and what explains everything. It must be a self-knowing, since both the knowing and the known must be infinite. What do we call something that is absolutely infinite, intelligent, necessary, and unchanging? This, to borrow St. Thomas Aquinas’ phrase, all men call God.