What is Metaphysics?
Metaphysics is not what is represented by the esoterica on display in some bookstores. It is not the subject you study if you want to learn about tarot cards and crystal healing and horoscopes. Instead, metaphysics is the rational attempt to make an inventory and classification of the sorts of things which exist and how these things are related to each other. At its best, metaphysics takes as its data the whole of human experience and tries to make sense of it using the tools of good reasoning. This experience includes our sensual experience of the physical world; subjective features of human thought and feeling; our experience of the people around us; aesthetic, moral, and religious experience; and scientific discovery and theorizing. All of this experience has led human beings to develop views, sometimes competing views, about exactly what kinds of things there are and how they are related.
There is a good deal of truth to the thought that each one of us, unless severely cognitively impaired, does at least a little bit of metaphysics and has metaphysical views. Examples of metaphysical views are that physical objects are the only things which exist, that human beings have immaterial souls, that the universe has always existed and will always exist, that there are angels, that there is such a thing as human nature which all human beings share, that God exists, that when a person dies he or she ceases to exist, that there are laws of nature, that there is such a thing as the geometrically perfect circle, that mathematics is one branch of fiction, and the logical complements of each of these views.
What makes someone a metaphysician in the vocational sense is a tenacious commitment to evaluating reasons for and against competing metaphysical views in pursuit of the correct, or at least most reasonable, views. There is nowadays a subfield of academic philosophy which goes by the name of metaphysics. Sadly, like most academic disciplines, academic metaphysics is devoted to gatekeeping jargon and nearly useless formalism which make it practically impossible for those who are not members of the guild to benefit from the expertise it cultivates. It is now dawning on our society that these cloistered conversations should not be conducted on the backs of indebted students and taxpaying citizens. We may lose altogether the academic class of experts in metaphysics, unless that class justifies its luxurious labor by shouldering a pastoral burden to help the non-experts think through life’s big questions carefully. But even if we do lose the academic class of metaphysicians, metaphysicians will still everywhere be found, some more tenaciously committed than others.
At its best, whether inside or outside the academy, metaphysical reasoning functions by proposing a metaphysical view as a good explanation of some data, where, again, the relevant data include all of human experience. A good explanation in metaphysics is usually taken to have the following features: logical coherence, explanatory power, parsimony, and elegance. Logical coherence is an all-or-nothing criterion: a view either has it or not. But the others come in degrees, and must be counterpoised: An extremely economical theory might not explain very much, and a theory with huge explanatory power might be excessively elaborate or clunky.
We can rationally select between competing theories by choosing the one which best meets these criteria. This is never easy, partly because reasonable people can come to different judgments about how explanatory power, parsimony, and elegance ought to be counterpoised in a particular context, and also partly because what counts as parsimonious or elegant is itself a topic of debate. For example, which is the more parsimonious metaphysics: a metaphysics which features very few things, or very few types of things, or very few logically discrete explanations of things? Metaphysicians will offer different answers. Also, elegance is inescapably an aesthetic quality, and our human ability to recognize and appropriately respond to aesthetic qualities is not exactly cultivated equally assiduously by all metaphysicians.
So, yah, metaphysics is hard. Because it is so hard, very few metaphysicians have the ambition to prove their preferred theories, where proof here is understood in a strong way as compelling a person to assent to what is proven, on pain of irrationality. Instead, a metaphysician nowadays will typically offer his theory as the one which better explains the relevant data than competing theories, or as the theory which should rationally be believed with a higher degree of confidence than competing theories.
For these reasons many people do not think it is worth the effort to embark on the metaphysical quest. You might think, even if there is the truth about metaphysics, it is not a truth I can know, so I should not spend my time thinking too hard about it.
I think there is something admirable in this attitude. I think it reveals a recognition that the truth worth knowing about is the truth to build our lives on, and that there is something perverse about building our lives on a particular theory which only narrowly edges out competing theories by standards which themselves are subject to dispute.
Despite my admiration for this attitude, however, I urge you not to adopt it. The fact is that we are all metaphysicians to some extent, at least in the sense that we do build our lives on metaphysical views. You are living a life right now. Your life includes beliefs, desires, goals, and habits and all these assume a foundational view of the way the world is: what things there are and how things are ordered to each other—in short, a metaphysics. You may not hitherto have thought very much about the metaphysics undergirding your way of life; it may have been given to you by your culture or your family or some profoundly wonderful or horrific experiences. However come by, you have it nonetheless. Upon reflection, you would probably see that some of your foundational commitments about the nature of reality are not commitments about which you could rationally claim certainty or even a high degree of confidence. And yet you have to live your life, and so live it on the basis of a metaphysical foundation. Why not make it a good one?