One of the things that students find frustrating about philosophy is that they don’t get definitive answers to the sorts of questions that philosophers ask. These students aren’t frustrated because philosophy doesn’t give them any answers. They’re frustrated because it gives them too many answers. For example, I teach a course on freedom and determinism in which the students learn (a) that the macroscopic universe is deterministic, so free will doesn’t exist, (b) that we can make choices that aren’t determined by prior events, so free will exists, or (c) that the macroscopic universe is totally deterministic, and we have free will. When students ask me which of these theories is true, I can’t tell them.  

If this were a scientific issue rather than a philosophical one, there would be a way to decide which of these views is the right one. All you’d have to do is gather the evidence, weigh it up, and see which theory matches the facts. But things work very different in philosophy. It’s not that we can’t lay our hands on the evidence that would allow us to see which if any of our theories is the right one. It’s that there isn’t any evidence for us to lay our hands on.  

The philosopher Peter van Inwagen nailed it when he wrote, “Disagreement in philosophy is pervasive and irresoluble. There is almost no thesis in philosophy about which philosophers agree.” Sure, there’s disagreement in science—especially at its cutting edge—but “there is a large body of settled, usable, uncontroversial theory and of measurements known to be accurate within limits that have been specified. The cutting edge of philosophy, however, is pretty much the whole of it.”

I’ll come right out and say that I DON’T think that philosophical disagreement is a problem—or, to put the point a bit more precisely, I don’t think that it’s a problem in quite the same way that many other philosophers seem to think that it’s a problem. And on the flip side, I don’t think that it’s NOT a problem in the way that lots of philosophers think that it’s not a problem either. I’m going spend the rest of this essay explaining why.

The question of whether philosophical disagreement is a problem is tied up with a nearby question: the question of whether philosophy has made any progress over the last twenty-five hundred years or so. Let’s go back to van Inwagen’s contrast between philosophy and science. Nobody can seriously doubt that science has made huge strides over the centuries. However interesting they might be historically, no present-day scientist thinks that texts from hundreds or thousands of years ago give us any insight into the workings of the physical world. Contrast this with those philosophers who take the work of guys like Plato dead seriously—not just out of historical interest, but because they think that Plato (or some other “giant” of philosophy) got the facts right.

Van Inwagen contrasts the existence of settled science—established knowledge that every scientifically literate person accepts—with the chaotic disarray of philosophical opinion. This comparison isn’t entirely right. Although it might not be obvious to outsiders, there is such a thing as (more or less) settled philosophy—claims that the majority of philosophers accept as true. But so-called settled philosophy isn’t on a par with settled science. Scientific controversies are settled by evidence. Chemists hold that chlorine atoms have seventeen protons because that’s what the evidence shows, Q.E.D. Even in the wilder, more unsettled regions of science—the cutting edge where evidence is thin and opinions are rampant—investigators look for evidence to settle controversies. That’s not to say that scientists are never pig-headed about their views, it’s just to say that they have methods for bringing opinions, sometimes kicking and screaming, before the tribunal of evidence.

Settled philosophy isn’t like that at all. For example, these days, most philosophers think that everything that exists is physical—that there aren’t any non-physical things. So, physicalism is more-or-less settled philosophy. But how come philosophers believe this? It’s not because they performed some crucial experiment or because they’ve surveyed the cosmos with a metaphysiscope. Convergence of opinion is only evidence of progress if it comes about in the right sort of way—namely, through the use of methods that give us an objective handle how the world is. But philosophers can’t appeal to such methods, because they don’t have any to appeal to. So convergence can’t be held up as demonstrating that we have moved forward like the scientists have.  

Here’s a different argument in support of philosophical progress. Have a look at Aristotle’s philosophy of biology, and then eyeball some present-day work in philosophy of biology. There’s just no escaping the fact that the modern stuff is a whole lot better than the ancient stuff. Isn’t that progress? Well, sort of. Ask why it is that present-day philosophy of biology is so much better than ancient philosophy of biology, and a big part of the answer—in fact, almost all of the answer—has got to be that biology has progressed. The engine of science has powered ahead and philosophy of science has come along for the ride.

I think that philosophy has made lots of progress—it’s just not made progress towards truth. If that sounds strange, you might have too parochial a view of what progress is. We tend to think of progress on the model of scientific progress—that is, progress towards truth. But why adopt a one-size-fits-all conception of progress? Why think that progress in philosophy is the same kind of thing as progress in science, or any other empirical discipline? As a man of sixty-three, I can lift a lot more weight in the gym than I could when I started lifting back in my thirties. That’s progress, but it’s not progress towards truth. Progress is just movement towards some goal. If your goal is truth, then progress is progress towards truth, and if your goal is bench-pressing a lot of weight, then progress is progress towards benching a lot of weight. It would be silly to say that my weight lifting hasn’t progressed because it hasn’t brought me any closer to the truth! So why fault philosophy for not having failed to get closer to the truth?

The question of whether philosophy has progressed can only be answered by answering a deeper question. What’s the goal of philosophy? What are we after—or rather, what should we be after—when we’re doing philosophy? Whatever the answer to this question is, it’s not the pursuit of truth. That’s not to say that philosophy can’t play a supporting role in the truth project. It certainly can. As the philosopher Daniel Dennett likes to say, “There’s no such thing as philosophy-free science.” Philosophy is a good worker but a bad boss. It’s great at helping out, but it should never be put in charge.

I hate to say it, but those philosophers who think that philosophy’s going to deliver truth are off on a wild goose chase. Some of these folks think that philosophy hasn’t produced what it should produce, and therefore that the theoretical pandemonium described by van Inwagen is a scandal. I disagree.

Others think that philosophy has in fact discovered truths. I disagree with this view too.

I disagree with both of these views because I think that philosophy is in the options business rather the truth business. Its job is to show that there are many ways of addressing a problem, and to spell out the implications of these alternatives. It’s because my students don’t understand that philosophy is in the option business that they complain that philosophy gives them too many answers, and this is also why I don’t think that having too many answers is a problem. Finding lots of answers, without having the resources, all on its own, to decide which of them are the right answers is what philosophy is all about.