Читать книгу What is Metaphysics? - John Heil - Страница 12

In embracing the categories of substance, property, and relation you would be betting that these would prove indispensable in any attempt to say what there is. Suppose you describe what is on the desk in front of you: a book, a pencil, and a tablet. (Your mobile phone is across the room.) To a first approximation, books, pencils, and tablets are propertied substances standing in assorted relations to one another. As you move further afield you encounter trees and rabbits, living substances. In front of you is a street sign, and a dustbin, and in the west the sun is setting. All of these things would seem to qualify as substances, all possess various properties and stand in various relations to one another, and to endless other things.

Moving beyond the everyday, you can find substances, properties, and relations in play in the sciences. Physics and chemistry speak of particles and atoms, for instance. Atoms themselves are made up of electrons, protons, and neutrons. These might be thought to be substances, possessing various properties (mass, charge, spin), and standing in assorted relations – spatial, temporal, causal.

Although we commonly take for granted that material bodies are made up of particles, we could be mistaken. What we treat as particles might turn out not to be granular, self-contained, mobile bits of matter, but to be energy concentrations in fields, or local thickenings in space. In that case, the fields or space itself would be the substances, and particles would turn out to be properties, modifications of fields or of space.

I mention these seemingly far-fetched possibilities only by way of example, only to illustrate the relation between the sciences, and particularly physics, and metaphysics. At the heart of metaphysics is ontology. Ontology offers a systematic account of categories of being or reality. If an ontology of substances, properties, and relations were adequate, you could see these as serving as what C. B. Martin calls placeholders, the details being supplied by the various sciences. If material bodies are made up of particles, for instance, the particles would be the substances. If particles were replaced by fields, the substances would be the fields. The sciences have a way of surprising us, evolving unpredictably. Still, it is not easy to envision a scientific revolution that dispensed with propertied substances of some sort, however strange.

I have emphasized the relation of metaphysics to the sciences, but the sciences are not our only avenues to knowledge. Poetry, music, fiction, drama, and their cousins have much to teach us. What distinguishes the sciences and makes them particularly relevant to metaphysics, especially ontology, is their systematic nature. You can learn much by reading Middlemarch or Harry Potter, or by watching High Noon or Crouching Tiger, Hidden Dragon: Sword of Destiny on Netflix, much that you would not encounter in a textbook on psychology or biology. Thinking of literature as in competition or incompatible with the sciences would be analogous to thinking of psychology and biology as in competition with one another and with physics and chemistry.

Although I shall often turn to the sciences to illustrate metaphysical themes, nothing I have to say here requires any sort of scientific sophistication. One reason for keeping the sciences in the foreground is that this serves as a reminder that metaphysics resembles the sciences in offering accounts of what there is – not by augmenting or supplanting scientific findings, but by providing placeholders for whatever categories emerge in the course of our most rigorous efforts to get to the bottom of things.