thoughts on universals

Recently, I've been trying to summarize my thoughts concerning universals. Making sense of these been a traditional problem in philosophy, and one sometimes finds oneself wondering if substantial progress has been made on it since Plato first articulated most of the issues. The fundamental difficulty is that universals, considered in themselves, are so fundamentally different from the particulars of everyday experience that many have justifiably wondered whether reflecting on them as entities in their own right is an altogether legitimate exercise. Individual objects – my car, say, or my coffee cup – have assignable locations at given times and cannot be at different locations at different times: or at any rate, for any given time period, a particular object like a car or a coffee cup must be found within a delimited spatial location. Conversely, a property like red can be instantiated in many places at once, and does not seem to be such that location and temporality can be meaningfully predicated of it apart from its instantiation, which might be anywhere and anywhen. Then, too, there is the mess of epistemological questions attaching to how we interact with and experience universals. Whereas I can see, touch, and lift my coffee cup, and perceive certain facts about it (e.g., that it is red) I cannot s'ee red', except in metaphor; indeed, while I can have direct experience of plenty of things that are red, it seems I can have no direct experience of red whatever, which begs the question of how I know that something is red when I see it. By the same token, the experience of the instantiation of universals has, or is alleged to have, a peculiarly personalized aspect with respect to the universal being instantiated. Another observer and I may both agree that the same object is red, but the red of my immediate experience isn’t the red of my neighbor’s immediate experience, or so it is often claimed. And finally, on the ontological side, we face the puzzle of why certain universals seem more fundamental, natural, or ‘given’ than others, despite the fact that there is nothing in the nature of the universals in question to explain this ‘givenness’. The property of being blue seems to us a simple attribute, inasmuch as we perceive it directly. Being blue between 4 and 5 p.m. in Peoria on December 26, 2007 and green thereafter is just as much a property, but one not so simple, not perceived, and not readily thought of: or so it seems to us. And there seems to be nothing in the nature of the properties themselves – blue, green, or ‘bleen’ – that helps us explain this.

I believe there's justifiable reason for thinking that we may be brought closer to a common resolution of these classical problems by acknowledging that less distinguishes universals from certain ‘3D’ particular objects than might at first be thought. In order to see why this might be the case, it helps if we first focus on an entirely different set of philosophical problems having to do with persistence and change in three-dimensional objects. I said above that these cannot be in different locations at different times; really, the problem of how an object like my car or my coffee cup or Winston Churchill, something which is wholly present at a time, can be in different locations at different times, or have any attribute at one time and not at another is a bit of a puzzle. The root of this is the old Leibnizian doctrine of the indiscernibility of identicals which can be summarized with the claim that, if A is identical to B, then, for any given property P, A exhibits/instantiates/participates in P if and only if B exhibits/instantiates/participates in P. Plausible as this first appears, it has, or seems to have, the unsettling consequence that no object survives any change. Suppose, for example, that A is me at 2:00 pm May 11, 2008, before I cut my fingernails, and B is me at 2:05 pm May 11, 2008, after I cut them. There is at least one property that B has that A does not have, namely, B’s fingernails are shorter by a few millimeters. This is sufficient to falsify the claim that for any property P, A has P if and only if B has P; hence by modus tollens, A and B are not identical. The stock philosopher’s answer to this paradox - namely, that we can resolve the puzzle if we regard me as a temporally extended object, with A and B as distinct and non-temporally overlapping spatio-temporal parts – seems a little pat, however. I (and other seeming-three-dimensional objects as well) do not feature obviously temporal parts; or to put it another way, while there is indeed a temporally extended thing with distinct temporal parts or phases relating to my activities, namely, my lifetime, this is something which seems to be conceptually distinct from me. The thing to see, I think, is that the problem of how I can be at different points in space-time in the company of different accidental attributes, and how red can be at different points in spacetime accompanied by different accidental attributes are really the same problem, and that this problem, if not solved outright by the recognition, is at least ameliorated by the recognition that 3D, temporally unextended objects really are much more like a kind of highly specialized universal than they are like what has been traditionally considered particulars. The only true particulars, on this view, are temporally extended, four dimensional entities: sections of the space-time continuum. These exhibit various properties, including the properties that serve to define their spatiotemporal boundaries; certain clusters of what are from our point of view highly specialized properties constitute 3D objects that may be said to be instantiated or implemented by the underlying processes.

But which properties? More specifically, what determines which properties are essential or necessary to the definition of a three-dimensional object, and which properties are merely accidental? We can add to this the related question of what makes certain properties seem more fundamental, more 'given' than others, so that blue seems somehow simpler and more basic than 'bleen'. This brings us to what is the real fly in the ointment of universals so far as I'm concerned, and that is salience. In some sense it is the key to the whole questions of why universals matter. Consider: if I delineate a particular chunk of space-time (the bit occupied by my coffee cup, say, while it is sitting on the countertop between the hours of six and seven p.m., central standard time), there are a lot of things that can be said about it. It is red. It has a certain mass, and at the point that it is in Earth's gravity field, a certain weight. It is a certain distance, readily measured in meters, from the local surface of the Earth, and a certain distance, readily measured in light years, from Alpha Centauri, varying very slightly over the interval in question due to Earth's rotation, Earth's movement in its orbit around the Sun, the Sun's and Alpha Centauri's mutual movement around the center of the Milky Way Galaxy, etc. A certain number of interactions will occur between the surface occupying the boundary of the space and a number of molecules of oxygen, nitrogen, trace gases in the local atmosphere. A certain set of photons in the local EM field will be absorbed at this same surface, and a certain set will be reflected. Not only this: not only can a practically infinitary set of features be described, there are a great many more ways of ontologizing these features than there are grains of sand on the seashore. But critically, only certain of these features exert a causal influence on us, or more properly, on our lifetimes, through the medium of our sensory apparatus. The key question is, why. Why do organisms pick out certain features as salient and essential to the construction of the 'object' in whose equally-constructed lifetime they inhere? What determines this relevance?

It seems clear that the story, here, must involve natural selection: however, having said that we must also acknowledge that that pronouncement can't be regarded as explanatory unless we can do more than just frame a story about how extracting this or that feature-set from the plenum pays off in terms of survival for some organism. On the foregoing analysis, organisms, considered as three dimensional 'objects', are nothing more than bundles of features themselves. The way to avoid circularity, I think, is via what we might term autocatalysis, following S. Kauffman. Without going too deeply into the technicalities, the idea is that certain sets of features are self-perpetuating, in the sense that they facilitate thermodynamic work cycles that store and release energy in a controlled fashion that acts on the environment in a way that serves to maintain a set of boundary parameters that in turn maintain the autocatalytic feature set. Such an autocatalytic system, considered as a set of features, is self-perpetuating, and therefore, self-relevant: moreover, inasmuch as such a system is responsive to its ambient environment wherein survival depends upon response, certain environmental conditions will be relevant as well, and a priority will be imposed such that some conditions will be more relevant than others. The saliency that I've written of - the reason why certain features seem perceptually given and fundamental - is owing to this environmental relevance for the autocatalytic system, and the ability of descendants of reproducing systems to continue leveraging from it in new ways. The greater part of human color perception, for example, arguably derives from the need of generations of our ancestors to be able to discriminate food sources from their surroundings in a wide variety of lighting conditions. Objectively, there are as many features available for distinguishing acorns from surrounding foliage as there are for distinguishing ripe apples, but human ancestors did not evolve eating acorns. The feature set and computation we happen to use for distinguishing ripe apples among many other things happens to be 'red'. The construction of universals in general, and 3D 'objects' in particular, is thus contingent upon the appearance of autocatalytic processes exhibiting self-sustaining feature sets. Such a view requires us to be realists about causal dependencies among feature sets, but this seems a small price to pay for an answer to the salience question.

In short, we interact with universals causally, in virtue of the fact that, as organisms, we are feature-sets ourselves: self-perpetuating, and hence, self-relevant and self-essential. 'Simplicity' in universals has little to do with the intrinsic complexity of the feature in question, and everything to do with the computational optimization of our sensoria for detecting and leveraging from it, and to its relevance vis-a-vis survival value to our species' historical and characteristic way of making a living. We need not be irrealists about universals, but their relevance to us (pursuant to the way we construct every-day three-dimensional objects) is what it is in virtue of our species' evolutionary history - and hence, is highly contingent. Insofar as discrimination may be identified with appropriate response, individual survival in natural selection just is discrimination of autocatalytically relevant universals.

References:
Goodman, N. Fact, Fiction, and Forecast, Fourth Edition. Harvard University Press (2006).
Kauffman, S. Investigations. Oxford University Press (2000).