I.

It’s often said that the first philosopher was Thales of Miletus, born in the 7th century BCE. His big idea was that everything is made of water. In hindsight, this is not such a good idea. Even watermelon is only 92% water. But there’s actually a very profound thought in Thales’ idea. To wit: although the world seems like it’s made of so many different things, of all different colors and shapes and sizes and consistencies, behind this appearance of baffling multiplicity lies a hidden unity. Deep down reality is one – even though appearance is multiform. It’s this insight that earns Thales his status as the first philosopher, not the bit about water.

Figure 1. Thales: Philosopher aquatic

Philosophy, then, starts with a fairly speculative idea, an idea in two parts. The first part is that there is a potential gap between appearance and reality: the world appears to us one way, but in itself it may be quite a different way. The second part is that the world in itself, the world as it really is, has a deeper unity to it, a hidden and subterranean interlocking of parts that underlies and surreptitiously runs through the jungle of variegated appearances. If we can uncover the hidden unity in the world, we would come to grasp the deep nature of reality. And that’s the goal of theoretical philosophy.

In this respect, the philosophical instinct has a tinge of mysticism about it. The mystic, too, believes in a hidden, somehow more noble reality hiding behind a veil of appearances in which we’re imprisoned in everyday life. And perhaps the mystic’s deepest conviction is that all division and opposition are an illusion, and true reality has an immutable oneness to it.

The mystic also has another core conviction, however, and this one can’t be farther from the philosopher’s way of seeing things. It’s the notion that the meticulous exercise of analytical thought is only an impediment to seeing the world aright. Genuine grasp of the nature of reality comes to us – the fortunate among us – in one fell swoop, one blessed moment, a single unmediated experience of the wholeness and oneness of reality (and, typically, of our own oneness with it). This exalted moment of insight changes everything: after it nothing looks or feels the same, and our life enters a higher level of consciousness. Crucially, thinking too much will not lead you there, according to the typical mystic – it will only lead you astray.

All this is very foreign to philosophy, which on the contrary regards with great suspicion such irresistible promises of instantaneous revelation and subsequent salvation. Philosophy’s gambit is to unfurl the deep unity of reality through the relentless but slow, almost tedious toil of careful, methodical, hyper-analytic reflection. It’s of course very tempting to dismiss painstaking rigorous analysis, since that’s the kind of thing that can be very difficult and frustrating, and is almost nobody’s idea of unbridled fun. But for the philosopher, the promise of a single moment in which a person, totally passive, would be blessed with complete and perfect insight into the nature of all things, therewith reaching everlasting peace of mind, is the biggest illusion. Climbing up the path to true understanding is a taxing affair laced with uncertainty and intellectual disorientation, requiring ardent application and considerable tenacity. It moves forward exasperatingly slowly, in piecemeal fashion, and can’t be hurried at will. Its blessings, such as they may be, are earned.

II.

Its trust in rigor, precision, and analytic labor makes philosophy much closer to science than to mysticism. Modern science is nothing if not meticulous, methodical, and labor-intensive. It’s very responsible, and serious, about what we should believe and what we shouldn’t, always testing and re-testing every hypothesis. In this, science serves as an admired model to philosophy.

What does science tell us about the way the world is in and of itself? Of course our cosmos, understood as the totality of matter and energy, is an incredibly complicated and variegated thing. But according to modern science, everything in it – everything! – is made up of the same compact group of elements, the subatomic particles. In nuclear physics’ Standard Model, these particles are of two kinds: (i) fermions, notably electrons and quarks, which are like units of stuff, and (ii) bosons, such as photons, which mediate interactions between those units of stuff. Nuclear physics is the scientific study of these objects – fermions and bosons – and of the facts concerning them: what properties they have (what mass each has, what charge, etc.) and in what relationships they stand to each other (attraction, repulsion, etc.).

From this compact class of building blocks – this corpuscular elite – science tries to build up our entire universe. Very roughly, it goes like this. When you put together subatomic particles in the right way, you get atoms, the properties of which are studied notably by condensed-matter physics. When you put together atoms in the right way, you get molecules, the properties of which are studied by chemistry. When you put together molecules in the right way, you get cells, studied by cell biology. If fermions and bosons are the building blocks of matter, cells are the building blocks of life. Putting together cells in the right way gives you tissues, which you can put together to get organs, from which you can go on to organisms – all studied at different levels of biology. Figure 1.2 displays this hierarchical X-ray of nature that natural science has given us.

Figure 2. Natural science’s X-ray of nature

The X-ray of nature displayed in Figure 1.2 is a kind of synchronic representation of the cosmos – it tells us how the universe is organized in space. But science also gives us a diachronic representation of the cosmos: the story of the cosmos over time. Whereas the synchronic representation of the cosmos is framed in terms facts (facts about which objects there are, what properties they have, and what relations they stand in), the diachronic representation is framed in terms of events, as well as certain collections of events – read: processes – and causal relationships among them. Figure 1.3 is a visual rendition (by NASA) of this diachronic representation.

Condensing the known history of the cosmos into one paragraph, it goes like this. The founding event is the Big Bang, which occurred about 13.8 billion years ago. It took 300,000 years – a cosmic blink of an eye – for the cosmos to cool down enough for atoms to start forming out of particles. Eventually galaxies started forming – ours, the Milky Way, about 13.2 billion years ago, give or take some. Our Sun, and with it the Solar System, formed 4.6 billion years ago, and the Earth about half a billion years later. Life emerged around 3.5 billion years ago, but animal life arrived only circa 542 million years ago. The first mammals separated from other vertebrates 320 million years ago, the first hominids separated from other apes about 5 million years ago, and the first modern humans – homo sapiens – separated about 200,000 years ago. Whether Neanderthals were a separate subspecies of homo sapiens or their own species of homo is controversial, but regardless, they went extinct anywhere between 20,000 and 28,000 years ago, leaving us, homo sapiens sapiens, the only extant humans. Art – both visual art (as evidenced by cave paintings) and music (as evidenced by paleolithic flutes) – appears on the scene about 40,000 years ago, when we still shared the earth with Neanderthals. But it’s only after the Neanderthals died out and the last ice age ended (circa 15,000 years ago) that, about 12,000 years ago, organized agriculture started: instead of hunting and gathering, humans started to domesticate plants and animals; they started making their food as opposed to finding it. And it’s 5,000 years ago that many foundational elements of our contemporary world came “online” (mostly in Mesopotamia): urban civilization, trade, technological innovations (bronze, the wheel), and most importantly, writing. The earliest work of literature we have is the Sumerian-Babylonian “Epic of Gilgamesh,” composed over 4,000 years ago. The alphabet I am writing these words in derives ultimately from ancient Egyptian hieroglyphs, via the Phoenician symbolic innovations over 3,000 years ago.

All this belongs in what we call human “prehistory,” because it predates witness accounts. Human “history” starts in the middle of the 8th century BCE, and since the late 18th century is customarily divided into three great eras: antiquity, running until circa 500 CE, the Middle Ages, going for about a millennium thereafter, and modernity, from circa 1,500 to the present.

Figure 3. The big sweep of cosmic history

This, in very broad strokes, is what we know scientifically about the world, synchronically and diachronically. What does philosophy have to contribute here?

III.

The beginning of the answer is in the following observation. Science’s synchronic representation of the cosmos deals in various facts, notably facts concerning which objects have which properties. And its diachronic representation deals in various events, notably events in which some object acquires a new property and/or loses an old one, as well as causal connections between individual events and longitudinal causal processes. But the notions of fact and event themselves are presupposed by science, not studied by it – and likewise for the notions of object, property, and causality.

Micro-physicists, for example, study micro-physical facts and events. They study micro-physical objects like electrons and quarks. A micro-physicist can tell you what properties an electron or a quark has – what mass, what charge, what spin, and so on – and how they causally interact with each other in such-and-such circumstances. Thus if you want an answer to the question “What is the nature of an electron?,” the physicist is your go-to person. A cell biologist, meanwhile, would be your go-to person to answer questions such as “What is a bone cell?,” “What is a nerve cell?,” and “What is a stem cell?” This is because cells are the kinds of objects cell biologists study, and cell biologists know a lot about the various properties of different kinds of cells, as well as the processes that cells undergo in different circumstances. But although a physicist can tell you a lot about the nature of physical objects and a biologist can tell you a lot about the nature of biological objects, neither can tell you much about the nature of objects as such. If you ask either a physicist or a biologist “What is an object?,” you’ll most likely get a blank stare, before being told that, well, it depends on the object.

Likewise, you can ask a physicist “What are the properties of an electron?” and a biologist “What are the properties of a stem cell?,” but you can’t ask either “What are properties?” Neither has really reflected on what kind of thing a property as such is. Ditto for the notion of a fact as such: a chemist would be more than happy to answer a question like “What are the facts about the hydrogen molecule?” but wouldn’t know where to start with a question like “What are facts?” The notions of property and fact, like the notion of object, are indispensable for scientists’ work, but they’re notions that scientists just use, mostly without even being aware that their using them. It’s a bit like someone who was born blind and has been using a cane to get around her whole life, and now that she’s 80, she forgets that the cane is even there. She feels the world through the cane like we feel the world through our fingers. And just like we don’t feel like we’re using a tool when we’re using our fingers, she doesn’t feel like she’s using a tool when she feels her way around the grocery store with her cane. She takes the cane for granted as we take our fingers for granted – and as scientists take for granted such notions as object, property, and fact.

The same goes for the notions of event and cause, obviously. Historians of Greece and Rome study Greco-Roman events and paleontologists study events like the Late Devonian extinction, but neither investigates with any depth the notion of an event as such. What caused the Late Devonian extinction? That’s a very important question for a paleontologist. But “What is causality?” is not something that concerns them.  

No science studies the nature of an object qua object, property qua property, fact qua fact, or event qua event. All these fundamental categories, which structure and mediate our scientific (and non-scientific!) representation of the world, and which are shared and presupposed by all of the sciences, are in themselves science-free. Science does not and cannot question them, because in truth it can’t operate without them – using them is not one among several “options” that science can consider and select among. It must employ them when studying physical objects, chemical properties, biological facts, geological events, historical causality, and so on. In its curiosity about the world, science works with these notions, but it never trains its curiosity on them themselves.

It’s here that philosophy comes into the picture. If you want to know what a particle is, ask a physicist; if you want to know what a molecule is, ask a chemist; if you want to know what a cell is, ask a biologist; but if you want to know what an object is, ask a philosopher. Likewise, if you want to know what charge is, ask a physicist; if you want to know what conductivity is, ask a chemist; if you want to know what diffusion is, ask a biologist; but if you want to ask what a property is, ask a philosopher. The philosopher is the person who looks critically at all these notions that are completely taken for granted in our dealings with the world, both in everyday life and in high-stake science, and tries to generate a general theory of these most fundamental of categories. What is it to be a property and how is it different from being a fact? What makes something an object rather than a property or an event? What is the nature of events and what makes an event the event it is, rather than a different event? These kinds of question, digging into the anatomy of the most fundamental structures of the world as we represent it in science and beyond, are the province of no specific science. They are the business of philosophy.

IV.

In their incredible generality, these fundamental categories in terms of which we see and understand the world – object, property, fact, event, etc. – do a lot to unify our worldmodel.  There are many kinds of objects in what the Daoists call “the world of ten thousand things.” But they are all objects. There is a unity across them at least in that fundamental respect. Ditto for the very many properties that things have – they are all still properties. Thus objects, properties, and so on constitute a metaphysical skeleton of reality, an invariant structure underlying the manifold of appearances.

Arguably, these categories don’t only unify our experience of the world thus far, but also unify our experience so far with our future experience and indeed with every possible experience. To see this, consider that even our imagination seems to be governed by the fundamental categories we’ve been talking about. Your wildest dreams and daydreams may contain some very strange objects with very weird properties, but it’s still objects and properties. Or take surrealist art. Here’s one of my favorite surrealist paintings, Yves Tanguy’s “Azure Sky”:

Figure 3. The big sweep of cosmic history

I can’t for the life of me tell you what any of these objects are, but I can tell you that they are objects. And also that they have various color and shape properties, and stand in various relations, including spatial relations such as being-nearer-x-than-y and physical relations such as being-linked-by-strange-white-thread. Tanguy clearly had a lively imagination, but even his imagination couldn’t break free from the basic framework of objects, properties, and relations, all arranged spatially.

We can see, then, that the fundamental categories we’ve been discussing impose an inescapable unity on our worldmodel. It is not the absolute unity that Thales sought, in which a single invariant element ran across all of being, albeit wetly. But there’s still relative unity here: a compact group of invariant aspects across reality. The identification of these categories thus speaks to the rationally-unifying impulse that characterized the emergence of philosophy.

And there is a recurrent strand in the history of philosophy that seeks to reduce even this compact group of categories to a single underlying and all-encompassing category, thereby generating a “one-category ontology.” This often passes through analyzing objects as collections of properties, or properties as collections of objects, or both objects and properties as different kinds of collections of facts, or of events. All of these have been tried. Success in one of them would deliver the mystic’s dream of revealing The One which is everywhere and is alone unbreakably real – though still without personifying it and imagining we can have a personal, affective relationship with it. No vistas of salvation are promised here, just a sui generis type of intellectual satisfaction.

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Uriah Kriegel is Professor of Philosophy at Rice University. He is the author of Subjective Consciousness: A Self-Representational Theory (OUP, 2009), The Sources of Intentionality (OUP, 2011), The Varieties of Consciousness (OUP, 2015), Brentano's Philosophical System: Mind, Being, Value (OUP, 2018), and Oxford Studies in Philosophy of Mind: Volume 4 (OUP, 2018).

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