Or suppose the question on the table is “What is the relevant level of description for explaining a person’s action?” And let’s say, to make the conversation around the table even more charged, that the action under discussion is of a kind to make the person come under judgment as either guilty or innocent of a crime of some kind. Is the right level of description the state of the brain before and during the time of the action? Or is the relevant description one that displays the action as an expression of the person’s character, embedding the action in a more extended narrative of who this person is? Though the physical terms deemed relevant would be new to Plato—the prefrontal lobe and the right temporoparietal junction, the amygdala and dopamine—the general philosophical argument would be familiar to him, as talk round the table focused on the “explanatory gap” between the neural and the narrative descriptions. After all, Plato could lay claim to having first formulated something like this explanatory gap when he considered the explanation for Socrates’ decision to stay in prison rather than fleeing to save his life.5
Or suppose the topic of conversation at the seminar table concerns whether abstract entities, such as numbers, truly exist. Mathematicians prove all sorts of truths about numbers, truths that often assert the existence of certain numbers (for example, given two rational numbers, there exists a rational number between them) and sometimes the non-existence of certain numbers (for example, there exists no largest prime number). But what does this talk of mathematical existence amount to? Do these proofs really have to do with existence in the same way that tables and chairs, the moon and the sun, and you and me exist? Or is mathematical existence something like saying that a particular move exists in chess—say, when a pawn has moved completely across the board to a square on the opponent’s back row and can be exchanged for any piece, not just a piece that your opponent has captured, which can result in your having, say, two queens on the board? Is that what mathematical existence amounts to, simply being the logical consequence of stipulated rules? Or is the existence asserted in these proofs something like existence in fictional worlds, where it is no less true that Hamlet was born in Denmark than that Hamlet, being purely fictional, was never born at all?
When the subject is mathematical existence, then Plato would be delighted (or maybe embarrassed) by how central to the argument raging around the seminar table his eponym is. The exact terms of these arguments would be unfamiliar to him—with new mathematical results enlisted pro and con—but the question of “mathematical Platonism” would be front and center. Only last week, an acquaintance sent me an updating email and added this postscript: “This fall I sat in on a seminar on Boolean-valued models forcing extensions of the set-theoretic universe.” He then listed the names of the mathematicians and logicians attending, a stellar constellation, and continued, “Very difficult stuff, but utterly beautiful. Arguments over Platonism raged the entire time.”
Yes, it’s true. A certain percentage of those questions still swirling around philosophy’s millennia-spanning seminar, the participants still going at them with everything they’ve got, were first posed by Plato—and often the “everything they’ve got” was first gotten to by Plato, too. So comfortable would Plato feel seated at philosophy’s seminar table that Alfred North Whitehead could famously write, “The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato.”6
Those predisposed to dismiss philosophy—some of my best friends—might hear in Whitehead’s kudos to Plato a well-aimed jeer at philosophy’s expense. That an ancient Greek could still command contemporary relevance, much less the supremacy that Whitehead claimed for him, does not speak well for the field’s rate of progress. Of course, not all philosophers would assent to Whitehead’s “safest general characterization of the European philosophical tradition.” But that lack of agreement in itself bolsters a philosophy-jeerer’s charge that philosophy never can establish anything.
The reason that some of my best friends are philosophy-jeerers is that many of my best friends are scientists. I do not mean to assert that the majority of scientists are hostile to philosophy. I’ve known scientists who are philosophically impressive. But there is, in a significant segment of the scientific culture, so ingrained a prejudice against philosophy that, much like other prejudices, people casually express their biases without even realizing they are doing so. To quote from a random example that is fresh in my mind, having read it this morning in a short item in Science magazine reporting on the search for “Goldilocks planets,” those neither too hot nor too cold to support life: “Just two decades ago, most considered the question of life elsewhere in the universe a fringe topic, more suitable for philosophy than for scientific research.”7
The casual equating of philosophy with topics on the fringe, emptily speculated upon, can pass unremarked in scientific circles. Like most prejudices, this one is usually not reasoned out, although sometimes it is. Sometimes a scientist is willing to stand up and bravely defend the claim that philosophy is worthless. “Philosophy used to be a field that had content, but then ‘natural philosophy’ became physics, and physics has only continued to make inroads,” Lawrence Krauss, a cosmologist who writes popular science books, told an interviewer. “Philosophy is a field that, unfortunately, reminds me of that old Woody Allen joke, ‘those that can’t do, teach, and those that can’t teach, teach gym.’ And the worst part of philosophy is the philosophy of science; the only people, as far as I can tell, that read work by philosophers of science are other philosophers of science. It has no impact on physics whatsoever, and I doubt that other philosophers read it because it’s fairly technical. And so it’s really hard to understand what justifies it. And so I’d say that this tension [between philosophy and science] occurs because people in philosophy feel threatened, and they have every right to feel threatened, because science progresses and philosophy doesn’t.”8
There are many things that one can say in response to this position. For starters, one could point out that the position presupposes that we have a clear criterion for distinguishing between scientific and non-scientific views of the world. When pressed to give the requisite criterion, scientists almost automatically reach for the notion of “falsifiability” first proposed by Karl Popper. His profession? Philosophy. The Kraussian position also presupposes that fields like relativistic quantum field theory (the very theory that, according to Krauss, is helping to render philosophy obsolete) are offering us descriptions of physical reality, even though they employ concepts which refer (if they refer) to unobservable states and entities, such as, to take a non-random example, relativistic quantum fields. The view that the strange entities dreamed up in the models of theoretical physics, though unobservable, are nonetheless real (if the theory in question is true) is known as “scientific realism”—a substantive philosophical claim, countered by a view known as “scientific instrumentalism,” according to which such theories as relativistic quantum field theory are merely tools for making predictions of observations and are not about any actual things that exist in the world. In this view, the success of relativistic quantum field theory offers no reason to believe that there is any such thing as a relativistic quantum field.
Presumably physicists care about the “philosophical” question of whether they are actually talking about anything other than observations when they do their science. And indeed, scientific instrumentalism is by no means a conceptual toy constructed for the extended playtime of philosophers. The view itself was first fully formulated by the physicist Pierre Duhem,9 and many physicists, including Niels Bohr, a leading formulator of quantum mechanics, have advocated instrumentalism, often motivated by the strangeness of quantum mechanics, which puts up challenging barriers to straightforward realistic interpretations.10 (A realistic interpretation can give one far more reality than one had bargained for—the so-called multiverse.)11 Quantum strangeness was Bohr’s reason for advocating instrumentalism. Perhaps not su
rprisingly, other physicists disagree, and when they are disagreeing, they are going beyond the domain of theoretical science and plunging straight into philosophy of science. What they’re disagreeing about is the question of what it is, precisely, they are doing when they are doing science. Are they refining their instruments for observation or discovering new aspects of reality?
All of which is to say that one cannot make the claims for science that many philosophy-jeerers make without relying heavily on claims—such as the falsifiability criterion for scientific statements, or the assumption of scientific realism—which belong not only to philosophy, but to that “worst part of philosophy,” philosophy of science.12 So if philosophy has as little substance as Krauss claims, if there is no way to make progress in philosophical knowledge, then this is as serious a problem for a physicist like Krauss as it is for those who call themselves philosophers.
Krauss mentions the old Woody Allen joke, but I’m reminded of another joke:
After a lifetime of hard work and bad luck, Jake makes a killing in the stock market and buys a villa for himself and his bride of forty years, Mimi, on prime real estate in Miami Beach. The first evening that they’re settled in, he and Mimi go out on the patio to enjoy their view of the Atlantic Ocean, and Jake discovers that it’s obscured by the trees of their neighbors. It’s okay, says Mimi, trying to calm down her excitable husband, but Jake gets right on the phone with the neighbors, and, after extensive bickering, they agree that, if he pays for it, they’ll top their trees. The landscaping work is done, and Jake and Mimi take their positions that evening on the veranda. Alas, the topped-off trees still get in the way of the view. Jake calls the neighbors, demanding that the trees will have to go, right down to the roots, but this time the neighbors balk. It’s okay, Mimi is heard plaintively begging in the background, but Jake, determined that he and Mimi get the view that their years of scrimping and saving deserve, offers to buy the neighboring villa at an inflated price. The neighbors immediately agree, and, as soon as the papers are signed, Jake has the offending trees cut down. “You know,” Jake says to Mimi that evening, as they sit on the veranda drinking in their unobstructed view of the Atlantic Ocean, “there are some things that money just can’t buy.” Like Jake, some philosophy-jeerers don’t take into account all the philosophical cash they have to spend in order to arrive at their view.
But still, even if the most extreme philosopher-jeerer can’t altogether avoid relying on a bit of philosophy, Popperian or otherwise, isn’t there something to the charge that “science progresses and philosophy doesn’t”? After all, if Plato, a man who voiced misgivings about that newfangled technology of writing things down,13 can still find his place at philosophy’s seminar table, doesn’t that cast the field as a whole in a seriously non-progressive light?
No self-respecting physicist would declare that all of physics consists of a series of footnotes to Democritus, even though that Greek, a bit more ancient even than Plato, managed not only to conceptualize but also to name the atom.14 Nor would any biologist describe his field as mere footnotes to Aristotle, even though Aristotle, with pre-scientific prescience, first laid out the taxonomy of the animal kingdom. Why don’t these other ancients have the currency in these scientific fields that Plato still enjoys in philosophy?
The answer, delivered in unison by the chorus of philosophy-jeerers, is that the empirical sciences, so unlike philosophy, make palpable progress. Possessing the self-correcting means to test and dispose, they prod the physical world so that the physical world gets a chance to answer back for itself in the form of experimental evidence. If science oftentimes has charged off in some altogether wrong direction, believing, say, that fire is to be explained by the existence of a fire-stuff, phlogiston, or that life is to be explained by the existence of a life-stuff, the élan vital, then empirical testing will, sooner or later,15 disabuse science of such fictions. All mortals are fallible, even the smartest among us, including the scientists. We are prey to cognitive lapses, some of them built into the very machinery of thinking, such as the statistical fallacies we are prone to commit. (Cognitive scientists have recently taken on these cognitive lapses and biases as a subject for scientific explanation.16) Given these cognitive vulnerabilities, it would be convenient to have an arrangement whereby reality can tell us off; and that is precisely what science is. Scientific methodology is the arrangement that allows reality to answer us back. This arrangement was precisely what Karl Popper had in mind when he made falsifiability the criterion of demarcation between the scientific and non-scientific, the very piece of philosophy of science that so many scientists automatically reach for when asked to defend their view that science alone makes progress.17 Insofar as a claim about reality is scientific, it is, in principle, falsifiable, which means nothing more or less than reality’s being afforded the opportunity to answer us back. “Ah, so you think that it’s perfectly obvious that two events are either simultaneous or they’re not, regardless of which inertial frame of reference they’re measured in, do you? Well, we’ll just see about that!” Voilà, the theory of special relativity displaces Newtonian mechanics.
Philosophy, in contrast, is like one of those dreaded conversationalists whose idea of engaging with you is to speak endlessly at you, not requiring—in fact, actively discouraging—any response on your part, one idea engendering another in a self-perpetuating closed system (as in the classic definition of a “bore”: someone who won’t change his mind and won’t change the subject). In exactly the same way—which is to say, not at all—does the actual world get to be involved when it is philosophy that is doing the talking. And it’s exactly because philosophy is just such a one-sided conversationalist that its rate of progress is what it is—in a word, null. (Again, still quoting the philosophy-jeerers here.)
And it’s not just the empirical sciences that tell so damningly of philosophy’s folly of futility. Even mathematics, though just as abstract and non-empirical as philosophy,18 could hardly be said to consist of a mere series of footnotes to Pythagoras, the number-enchanted seer who died some sixty-odd years before Plato was born but whose mathematically dominated view of the universe had a profound effect on the younger philosopher. Mathematics could not be said to be a mere series of footnotes to any of the Greeks, including Euclid, who was born twenty-two years after Plato died and codified many of the proofs of his predecessors.19
Such ancient thinkers as Democritus, Aristotle, and Pythagoras have been left in the ancient dust by the fields of physics, biology, and mathematics. Democritus, intending to major now in physics, wouldn’t get very far with his freewheeling speculative approach and might well be taken aback by the great amount of mathematics—calculus in classical mechanics, for starters—that he would be required to master if he wanted to understand modern conceptions of matter and energy, space and time. The melding of experimental techniques with mathematical description was the great leap forward, accomplished in the seventeenth century, that brought us to the point at which, as Krauss put it, “ ‘natural philosophy’ became physics.”20 Democritus would also have to put in long hours in the lab, devising experiments under carefully controlled conditions, and taking measurements by means of instruments designed to extract precisely the right information. As for Aristotle, should he intend to major in biology his first assignment would be to master the theory of natural selection, together with genetics, without both of which he could not begin to understand any contemporary explanations for biological structures and functions. And then there is Pythagoras. The legend is that the founder of theoretical mathematics was so outraged when one of his students, the haplessly gifted Hippasus, discovered irrational numbers21 that he sent the poor fellow out on a raft to drown, initiating a venerable tradition of professors mistreating their graduate students. Pythagoras, should he want to continue on for a degree in modern-day mathematics, would have to learn to abide far more counterintuitive results than numbers that cannot be written as ratios between whole numbers. Fro
m the square root of −1, to Georg Cantor’s revelation of infinite domains infinitely more infinite than other infinite domains, to Kurt Gödel’s incompleteness theorems, mathematics has constantly displaced the borders between the conceivable and the inconceivable, and Pythagoras would be in for some long hours of awesome mind-blowing.
And all the while Democritus, Aristotle, and Pythagoras were getting remedial tutoring in their respective fields, our man Plato would be holding forth at philosophy’s seminar table. Isn’t this ample proof of something seriously awry with the entire field of philosophy?
But wait just a second here. Since Democritus, Aristotle, and Pythagoras are officially classified as philosophers, shouldn’t the field of philosophy get some credit, after all, for those progress-achieving, distance-making fields that left those ancients far behind? Not at all, responds the chorus of philosophy-jeerers. Oh, sure, philosophy, by spinning out questions in every direction, like a toddler who has just discovered the exasperating power of mechanically appending “Why?” to every received answer, has managed over the course of its excessively long history to occasionally put forth some good questions, by which is meant questions that have actual answers, instead of variations on those soundless-or-not-trees-in-the-forest non-starters for which no discoverable fact of the matter would count as any solution at all. Philosophers, asking and asking without ever possessing the means of answering, sometimes ask questions that are, so to speak, protoscientific, posed before the science yet exists that can pursue them effectively, which is to say empirically. But even though it’s the philosophers who ask the questions, it’s always the scientists who answer them. Philosophy’s role in the whole matter is to send up a signal reading “Science desperately needed here.” Or, changing the metaphor, philosophy is a cold storage room in which questions are shelved until the sciences get around to handling them. Or, to change the metaphor yet again, philosophers are premature ejaculators who pose questions too embarrassingly soon, spilling their seminal genius to no effect.
Plato at the Googleplex Page 3