Here is a powerful argument, often used in support of rationalism, that ontological nebulosity is impossible:
An object is just atoms, and atoms have precisely fixed, objective behaviors. So we know from physics that an object doesn’t depend on your subjective ideas about it. There’s only one real world. Different people may have different beliefs or concepts about it, but that doesn’t affect what’s true. We don’t each get our own reality; only our own subjective opinions. Your supposed “nebulosity” just boils down to people having different theories, some of which are true, and some of which are false. It’s just epistemological fuzziness. There’s no fuzziness in objective reality.
Quantum field theory is the closest thing we have to an absolute truth about physical reality. The physicist Richard Feynman was one of its major architects. He wrote:
What is an object? Philosophers are always saying, “Well, just take a chair for example.” The moment they say that, you know that they do not know what they are talking about any more. The atoms are evaporating from it from time to time—not many atoms, but a few—dirt falls on it and gets dissolved in the paint; so to define a chair precisely, to say exactly which atoms are chair, and which atoms are air, or which atoms are dirt, or which atoms are paint that belongs to the chair is impossible. So the mass of a chair can be defined only approximately.
There are not any single, left-alone objects in the world. If we are not too precise we may idealize the chair as a definite thing. One may prefer a mathematical definition; but mathematical definitions can never work in the real world.1
There are no absolute truths about an eggplant-sized object, because there is no absolute truth about which atoms make it up. The physical boundaries of a physical object are always nebulous, to varying degrees.2
Let’s follow Feynman’s argument in a more dramatic case, a wispy cloud. Some atoms are clearly in the cloud, and some are clearly out, but there’s a fuzzy margin. This is not a matter of uncertainty. There’s just no absolute or objective truth about whether some atoms are part of the cloud or not. Those could easily be ten percent of all the atoms that might reasonably be counted as part of the cloud. A cloud’s mass is roughly a million kilograms, so this “slop” is on the order of a hundred tons.
The mass of a set of atoms is objectively well-defined. But a cloud or a chair or an eggplant is not a specific set of atoms. If you look at the surface even of a stainless steel ball bearing under a powerful enough microscope, in sufficiently slow motion, in the same way there will be atoms loosely associated but not definitely either part of it or part of its surrounds.
Mass is a fundamental physical property. If the mass of an object is nebulous, how much more so its shape, compressibility, or pathogenicity?
The absolute truths of quantum field theory don’t apply precisely if you can’t say precisely what you want to apply them to. So, why not do that? Can’t we define precisely, mathematically, objectively what an object is? We could find some criterion that would tell us exactly which atoms are part of the cloud or chair. Something about density or homogeneity of composition or cohesive force.
We could do that—and it would be a subjective concept. It would involve arbitrary threshold quantities. Different people could reasonably choose different cut-off values: exactly how cohesive? There’s no objectively preferable answer. In some cases, tiny differences in the cohesion threshold would dramatically change what counts as “part” of an object; and no matter what the value is, the boundaries drawn by the objective criterion would often fail to correspond to anything useful. If you superglue a toothbrush to an eggplant, you don’t get one object, you get two objects stuck together with bonds stronger than the internal cohesive forces of either. On the other hand, there’s zero force binding together the water droplets that make up a cloud; they are just carried along in parallel by the wind.
The rationalist argument was that “we know from physics that an object doesn’t depend on your subjective ideas about it.” But Feynman tells us that we know from physics the opposite: “There are no definite objects in the world; mathematical definitions can never work.”
This doesn’t require any fancy physics. It doesn’t involve quantum indeterminacy. It’s sufficient that eggplants are made out of little bits (particles, atoms, molecules, whatever), and the bits are never either definitely stuck together or not. There are just attractive forces of continuously variable strength.
Misunderstandings of the nebulosity of objects
The non-objectivity of objects is easy to misunderstand. Several subtle misinterpretations are common.3 I’ll explain some briefly here; I intend to cover this in much greater detail elsewhere in Meaningness eventually.
Objects don’t exist, and eggplants are objects, so eggplants don’t exist. Obviously eggplants exist. That isn’t the issue. The issue is that the universe is not intrinsically divided into chunks; certainly not at scales larger than molecules. The problem is not objects, exactly, but objective objectness: qualities of solidity, durability, separateness, homogeneity, and identity.4
Objects are subjective, arbitrary, or conjured into existence by a mental act or social convention. Pluto was there before Clyde Tombaugh discovered it in 1930, and it is not impressed with anyone’s opinions about it. Its atmosphere is tenuous, and loses approximately 5 × 1025 molecules of methane every second. On their way out, there’s no objective truth about when they cease to be part of Pluto. However, the existence of Pluto is not subjective. Reality is not divided into chunks, but it is elaborately patterned. Objective and subjective do not exhaust the possibilities. Objects arise in interaction.5
Objects have a definite, unitary core, giving them an identity; they’re just fuzzy around the edges. Not true in general. If it were, there would be a fact about how many clouds there were in a particular region. But whether or not two dense bits of cloud are “connected” by a wispier bit (and therefore parts of one cloud), or not (and therefore two separate ones), is not objective.
It’s about physical nondeterminism. If all motion in a cloud and its vicinity suddenly stopped permanently, the cloud would still be indefinite, although perfectly deterministic. Quantum indeterminacy is mostly irrelevant to nebulosity. Dynamical chaos (macroscopic de facto nondeterminism) does add to nebulosity, but it’s not necessary for it.
It’s about emergence. The concept “emergence” addresses some of the same problems as “nebulosity,” in quite a different way. The idea is notoriously confused, and it’s not clear there is any coherent version.6 That makes it somewhat difficult to say exactly how the two differ. However, emergent entities and properties are generally taken to be objective: independent of contexts and purposes. Nebulous objects and properties generally aren’t.
Objects, rationality, and reasonableness
Rationally-held beliefs are mostly about indefinite objects—magmatic dikes, mold sprues, killer-T cells—and in science and engineering we have to accept this as a fact of life.
“If we are not too precise we may idealize the chair as a definite thing,” said Feynman. In rational practice, we use ontologies that assume the existence of definite objects with definite properties. Such an idealization cannot precisely reflect the real world, because there are no such. “One may prefer a mathematical definition; but mathematical definitions can never work in the real world.”
So, why does this work? How can we choose ontologies that do work, despite not being “true”?7 How does a good ontology relate effectively to reality, if not as a faithful reflection? These are central concerns of meta-rationality, and main topics of Parts Three and Four.
In reasonable everyday activity, it’s usually not a problem that the world cannot be divided into definite objects. When you make an omelet, the butter, milk, and eggs mix partially, in no particular way. Your ability to work effectively with the non-objectness of these materials depends on non-rational skills of perception and manipulation, which can impose boundaries on their nebulosity. It also depends on a shielding technology: the frying pan, a container which limits the spread of their runniness. If the pan has a teflon lining, it can also mostly prevent the formation of chemical bonds between egg proteins and the pan, which would muddle a boundary unhelpfully. (As you know if you’ve cursed while scrubbing the result off an inadequately seasoned iron skillet.) Part Two further explains the effectiveness of reasonable, non-rational activity in indefinite situations.
Meta-rationalism explains the relationship between rationality and reality as mediated by reasonable activity, and as enabled by definiteness-enhancing technologies:
We can do science on magmatic dikes, and discover true beliefs about them, because we can distinguish them perceptually well enough for particular purposes, even though they don’t have objectively definite boundaries. Likewise, when a construction crew erects the bridge designed by a civil engineer, they use their non-rational arc-welding skills to translate the abstract geometric objects of the plan into somewhat messy physical realities.
Objects in the natural world—marshes and mountains, sticks and streams—are unhelpfully nebulous, which makes rationality difficult. “What sort of world would rationalism be true of?” One with objectively separable objects. How do we make the world more like that? By making objects more definite. For example, we machine them out of metal, or mold them from plastic, so they are rigid, homogeneous in composition, and have better-defined boundaries. We put indefinite messes (cell cultures, for instance) in containers to give them external boundaries, and to shield them from external influences. Rationality works because we’ve engineered the world to more nearly conform to definite ontologies. Shielding technologies, and other methods for making a rational ontology more nearly accurate, are a major theme in Part Three.
Science generally aims for universal, objective truths (and rightly so). However, when you apply rational conclusions to the real world, separation of objects is generally somewhat context-dependent and purpose-dependent. That is because (as we will see) reasonableness critically depends on context and purpose. It carves out chunks that are useful, meaningful, or explanatory.
Do cow hairs that have come out of the follicle but that are stuck to the cow by friction, sweat, or blood count as part of the cow? How about ones that are on the verge of falling out, but are stuck in the follicle by only the weakest of bonds? The reasonable answer is “Dude! It doesn’t matter!”
“It doesn’t matter!” is a major way reasonableness can deal with practical matters that formal rationality cannot. But, this is purpose-relative. If you are loading cows onto a truck, it doesn’t matter. If you are a veterinary researcher studying cow mange, it might matter a lot.
The meta-rational questions are: does it matter, for a particular purpose? If so, how and why? What does this imply about how we should deploy rationality?
- 1.The Feynman Lectures on Physics, Volume 1, Chapter 12, Section 1. Some phrases omitted for concision.
- 2.An excellent philosophical discussion, with compelling examples, is Alexandre Linhares’ “A glimpse at the metaphysics of Bongard problems,” Artificial Intelligence 121 (2000) pp. 251–270.
- 3.In analytic philosophy, the non-objectivity of objects is described as “the problem of the many,” or of “vague objects,” and has been a major topic for several decades. The literature is a mass of confusions. For an overview, see the Stanford Encyclopedia of Philosophy article “The Problem of the Many.”
- 4.I think this is probably why Feynman qualified “there are no objects” with “single, left-alone.” That’s not very clear, but a full explanation is complicated, and will run to many pages in Meaningness.
- 5.For an explanation of “neither objective nor subjective but interactive,” see “Rumcake and Rainbows” in Meaningness. Interactivity is one key to an accurate understanding of non-objectness, but this is a more philosophical topic than belongs in The Eggplant. The section on “Reasonable objects” in Part Two will give a taste, though.
- 6.As usual, I’ll suggest an Stanford Encyclopedia of Philosophy article for details: “Emergent properties.” Part of the problem is that “emergence” is taken as the natural alternative to “reduction,” which, as we saw earlier, is also incoherent. Unfortunately, simply inverting a bad idea rarely produces a good one.
- 7.In some cases, an idealization may be approximately true: we can put a numerical bound on the error in its predictions. As we saw in “Overdriving approximation,” that is not generally possible.