Realism and interfaces in philosophy of mind and metaphysics
November 30, 2014 7 Comments
In an earlier post, I discussed three theories of perception: naive realism, critical realism, and interfaces. To remind you of the terminology: naive realism is the stance that the world is exactly as we perceive it and critical realism is that perception resembles reality, but doesn’t capture all of it. Borrowing an image from Kevin Song: if naive realism is a perfect picture then critical realism is a blurry one. For a critical realist, our perception is — to move to another metaphor — a map of the territory that is reality; it distorts, omits details, adds some labels, and draws emphasis, but largely preserves the main structure. Interfaces, however, do not preserve structure. Borrowing now from Donald Hoffman: consider your computer desktop, what are the folders? They don’t reflect the complicated sequence of changes in magnetization in a thin film of ferromagnetic material inside a metal box called your hard-drive, not even at a coarse-grained level. Nor do they hint at the complicated information processing that changes those magnetic fields into the photons that leave your screen. But they do allow you to have a predictable and intelligible interaction with your computer, something that would be much more difficult with just a magnetized needle and a steady hand. The interface does not resemble reality, it just allows us to act. Although the comments section of the earlier post became rather philosophical, my original intention was to stay in the realm of the current scientific discourse on perception. The distinction between realism and interfaces, however, also has a rich philosophical history — not only in epistemology but also in metaphysics — that I want to highlight with a few examples in this post.
It is hard to find a strong philosophical proponent of naive realism, but I think Epicurus might be the strongest contender. Epicureanism focuses on sensation as the first criteria for truth — our sensations are not subjective and cannot deceive us about the external world that they attest to exist. Any falsehoods or deceptions enter into our experience only through the application of preconceived notions or categories to our sensation. These categories are fundamentally linked to language, and form the meaning underlying the word. It is tempting to equate this Epicurean empiricism with naive realism — in that the world is really like our sensation of it — but it is not clear to me that it would correspond to a theory of perception. Perception is not mere sensation, but also incorporates the Epicurean preconceived notions — once these are combined, we can systematically misrepresent the world, and thus have critical realism or even an interface theory, depending on the accuracy and source of our preconceptions. However, I think that the materialist nature of Epicurean thought has a lot of appeal to modern scientific readers, and so is a good historic source for naive and critical realism.
Surprisingly, you don’t need to be a materialist to embrace critical realism. In fact, you can build a whole non-materialist metaphysics around critical realism as Plato does vividly in the Allegory of the Cave. Our perceptions are like the shadows on the cave wall, created by — and in many aspects mimicking the properties of — the puppets that our captors set dancing to be illuminated by the flames behind us. Except for Plato, this metaphor is not meant to be limited to our perceptions — towards which I think his characters actually took a more naive realist view — but the whole material world, the objects of the world are just blurry photographs, imperfect maps, or shadows of the eternal world of Forms. These Forms give material entities their properties — like the Form of Beauty giving your significant other their beauty — and thus the material help us to remember the Forms — how studying your partner’s face helps you understand what it means to be beautiful — that your soul knew before the trauma of birth. An essential aspect of these forms — apart from their causal powers, which might seem particularly uncomfortable to the modern reader — is that many of the same properties can be applied to them as to the material objects that share in the Form. The sensibility of properties of perceptions in being applied to the perceived, is the hallmark of a realist theory.
Of course, critical realism was not confined to ancient Greece. It is alive and well today, and I want to touch an early twentieth century embrace — Russell’s (and to a much lesser extent, early Wittgenstein’s) logical atomism. Russell and the early analytic philosophers that followed him believed that language reflected the structure of reality. In this way, we could see them as picking up where we left off with Epicurus and being optimistic about the accuracy of our preconceptions. By studying language, we could arrive at the logical atoms that underlie meaning and through them understand reality. Of course, in the process we might learn that some of our sentences are shorthand for much longer logical statements, and that some sentences are even empty of meaning. If we follow the less optimistic Wittgenstein then we can even start to depart from critical realism, by seeing language as a veil that hides and distorts our underlying thought. In terms of Epicurus, by analyzing language we can come to discover in what way our preconceived notions fundamentally misrepresent reality, and thus arrive at an ineffable mystical understanding of the world. In my books, Russell’s optimist would clearly place him as a critical realist, but I can make less sense of Wittgenstein. For me, Wittgenstein’s direct mystical understanding of reality would qualify as a naive realism in its transcending of the Epicurean preconceived notions, but I don’t know how to classify his discussion of language (is it an interface to reality?) or if classifying it is even useful.
For full-fledged interface theories, although we can also find roots in ancient Greece — see for instance Parmenides‘s distinction between the way of truth and the way of opinion — I think the first sophisticated versions of this view originated in the late ancient and medieval times. The questions here were primarily concerned not with the material world but with the nature of God, and the main sources of evidence were not sense-data or experiments but syllogisms and scripture. However, similar philosophical tensions arose. For many philosophers, God was immaterial and had an existence that was distinct from that of the conditional existence of worldly things. Yet, infallible scripture spoke of God’s physical properties like hand, back, or throne or intellectual properties like power, mercy, wrath, and love. For interface theorists, these statements were meant as allegories, metaphors, and helpful presentations of God, but in no way reflective of God’s true nature. Rationalist thinkers like Averroes saw these scriptural interfaces as sent to be used by those who were not fortunate enough to dedicate themselves to philosophy. Sufi mystics like Ibn Arabi or Rumi extended these interfaces to a full metaphysics by suggesting that the whole of the universe was a veil disguising the one-ness of God. Like Wittgenstein much later, they would suggest an unveiling through transcending language.
Finally — and before you decide that I’ve abandoning all notions relevant to modern science — let me briefly mention Kant and quantum mechanics. To me, Kant is the most important interface theorist, for him the organization of our sense-organs create the phenomenal world as an interface with the thing-in-itself that we can have no direct experience of — kind of how I can’t really have a (meaningful) direct experience with the bits of magnetization in my hard-drive (or on the hard-drives of WordPress data centers) that ‘are’ this post. One of the most important structures of the phenomenal world created by our senses in this way is space and time. The conclusion that Kant arrives at — recast in Hoffman’s metaphor of a computer desktop — is that just because I can say that on my desktop the file for this post is to the left of the file for my most recent paper, I can’t say that the bits of magnetization that make up this post are to the left of the bits of magnetization that make up my paper (this can be further complicated by the fact that this post is actually on WordPress servers and my recent paper is on WriteLatex servers). Just because the interface has some structure, does not mean that this structure has to be a reflection of reality.
Kant’s viewpoint is important not only for philosophers, but appears in the interpretations of quantum mechanics. If you’ve ever heard of quantum mechanics, you have probably heard some form of Heisenberg’s uncertainty principle like “you can’t know both where you are and where you’re going”, or more formally: the position and momentum operators do not commute. If you investigate this facet of quantum mechanics as deeply as John Stewart Bell then you will see that any interpretation that is mathematically consistent with quantum mechanics will need to abandon realism or locality. Bohr’s interpretation — although made before Bell’s theorem was discovered — went the route of following Kant and abandoning realism. For Bohr, our experimental practices need to be grounded in pre-scientific concepts like space and time — in particular, the concepts of position and momentum are the formal specifications of these constraints of our phenomenal experience. Reality is not constrained in the same way as our perception, and so when we try to speak of nature in terms of our phenomenal categories — as we must in order to be able to communicate our experiences — we create the properties necessary for our interface. However, these properties — position and momentum, specifically — only exist in our interface with reality and not in reality itself. Thus, Heisenberg’s uncertainty principle is an expression of the tension between our perceptual interface and reality. Here perception is meant much more widely than human senses like eyesight and touch, and extends to all of our possible technological senses or experimental techniques: all of science serves as our interface.
Of course, this is not the only interpretation of quantum mechanics. We could also take the other horn, and give up locality as Bohm does, in order to preserve realism. We could also simply play with the meaning of ‘real’ and create three separate realities: manifest, scientific, and thing-in-itself; with the first giving us naive realism, the second — critical, and the third we can only interface with through the prior two. At that point it becomes tempting to declare “what is really real” between those three options to be a matter of taste.