Several readers sent me a link to yesterday’s Guardian dialogue between philosopher Julian Baggini and physicist Lawrence Krauss, “Philosophy v. science: Which can answer the big questions of life?” You should read it.

Baggini has previously taken strong stands against “scientism” (which he defines in this piece as the insistence “that, if a question isn’t amenable to scientific solution, it is not a serious question at all”), and Krauss has disparaged philosophy (though he backtracked a little subsequently). Despite these differences their dialogue is surprisingly good and productive, resulting in some fundamental agreements.  Both men make good points.

Baggini uses, as an example of a question that isn’t susceptible to a scientific answer, “What is the moral thing to do in a given situation?”. But he agrees, as we all do, that the answers to such questions can be informed by science (which I define broadly as empirical study resulting in verifiable information about the universe):

[JB]: My contention is that the chief philosophical questions are those that grow up without leaving home, important questions that remain unanswered when all the facts are in. Moral questions are the prime example. No factual discovery could ever settle a question of right or wrong. But that does not mean that moral questions are empty questions or pseudo-questions. We can think better about them and can even have more informed debates by learning new facts. What we conclude about animal ethics, for example, has changed as we have learned more about non-human cognition.

When Sam Harris came out with The Moral Landscape, maintaining that morality did have a scientific basis, requiring the answer to the question “What maximizes well being?”, I was dubious.  After all, even that requires a value judgment: increasing “well being” is what we think is moral. In most situations that’s true, for our notion of morality may be coterminus with well being. But that might not always be the case. And how do we quantify different forms of well-being when we have to trade them off against each other?

Now, however, I’m coming around to Sam’s view.  People’s view of what is “moral” ultimately must rest on one or more of three things: an appeal to the consequences, an appeal to some authority (like Scripture), or some innate feeling instilled by our genes in combination with our environment (in other words, morality lies in our neurons). Sam’s answer is a combination of the first and third, but regardless, both the first and third are susceptible to empirical investigation.  (For most people Scripture is ruled out as a source of authority, simply because almost nobody—with the exception of wackos like William Lane Craig—adheres scrupulously to the morality embodied in sacred books).

In the end, then, it is possible, though not yet feasible, for science to determine what is moral, simply by investigating the neurological and evolutionary bases of our value judgments. In the meantime, we employ philosophy informed by science.  In the end, it will be the other way around: moral questions will be answered by science informed by philosophy, for, after all, it is philosophy that enables us to think hard enough to pose moral dilemmas and discern what people mean when they say “right” and “wrong.”

The two have a similar exchange over the morality of homosexuality. Krauss asserts that it can’t be immoral because it has a biological basis and, judging empirically, is not harmful:

[LK]: Take homosexuality, for example. Iron age scriptures might argue that homosexuality is “wrong”, but scientific discoveries about the frequency of homosexual behaviour in a variety of species tell us that it is completely natural in a rather fixed fraction of populations and that it has no apparent negative evolutionary impacts. This surely tells us that it is biologically based, not harmful and not innately “wrong”. In fact, I think you actually accede to this point about the impact of science when you argue that our research into non-human cognition has altered our view of ethics.

Baggini replies with the time-honored response, which at first sounds reasonable:

Your example of homosexuality is a case in point. I agree that the main reasons for thinking it is wrong are linked with outmoded ways of thought. But the way you put it, it is because science shows us that homosexual behaviour “is completely natural”, “has no apparent negative evolutionary impacts”, is “biologically based” and “not harmful” that we can conclude it is “not innately ‘wrong'”. But this mixes up ethical and scientific forms of justification. Homosexuality is morally acceptable, but not for scientific reasons. Right and wrong are not simply matters of evolutionary impacts and what is natural. There have been claims, for example, that rape is both natural and has evolutionary advantages. But the people who made those claims were also at great pains to stress this did not make them right – efforts that critics sadly ignored. Similar claims have been made for infidelity. What science tells us about the naturalness of certain sexual behaviours informs ethical reflection, but does not determine its conclusions. We need to be clear on this.

But on what grounds, then, do we determine whether homosexuality is right or wrong? It must rest on an appeal to the consequences (which is an empirical and scientific question), on the way most people feel about homosexuality (something that is a combination of our genes and our environment, and coded in our neurons), on sacred books and dogma, or on a combination of these. Ruling out the third, the first two are, in effect, scientific questions.

Now that doesn’t meant that science can actually answer these questions, particularly if they involve evolution and neurobiology. What it means is that in principle science must be is the ultimate arbiter of moral questions.  And I think Baggini realizes this, for I left out the last sentence in his response above:

[JB]. . .It’s one thing to accept that one day these issues might be better addressed by scientists than philosophers, quite another to hand them over prematurely.

Here both Baggini and Krauss seem to agree that even the toughest philosophical questions might one day be amenable to science:

[LK]: Where I might disagree is the extent to which this remains time-invariant. What is not scientifically tractable today may be so tomorrow. We don’t know where the insights will come from, but that is what makes the voyage of discovery so interesting. And I do think factual discoveries can resolve even moral questions.

As for ethics, I think in principle it might be best to jettison completely our notions of morality, and simply appeal to consequences of behavior and how we regard them. That, after all, is the ineluctable conclusion reached if one is an incompatibilist like myself who doesn’t believe in free will. Krauss agrees:

[LK]: Moreover, that many moral convictions vary from society to society means that they are learned and, therefore, the province of psychology. Others are more universal and are, therefore, hard-wired – a matter of neurobiology. A retreat to moral judgment too often assumes some sort of illusionary belief in free will which I think is naive.

Now I’m not naive enough to think that we should immediately begin dispensing with the notion of morality and moral judgment, much less “right” and “wrong”. These ideas are so ingrained in all human society that discarding them is well nigh impossible, at least for the moment.  But in the end, we aren’t responsible for our actions in the way most people think, for they stem from aspects of our biology that we don’t understand and can’t control.

And for those of you who say that “is” doesn’t produce “ought,” I’d like to ask you this: “well, how do we determine ‘oughts'”?  They don’t come from thin air, and they don’t come from free will.  They come from human judgment, which is a result of our genes and our environments. Why is that not, at least in principle, susceptible to scientific investigation?

Where does this leave philosophy? As Baggini admits, many philosophical questions will ultimately yield to science:

[LK] . . . What isn’t ruled out by the laws of physics is, in some sense, inevitable. So, right now, I cannot imagine that I could computationally determine the motion of all the particles in the room in which I am breathing air, so that I have to take average quantities and do statistics in order to compute physical behaviour. But, one day, who knows?

[JB]: Who knows? Indeed. Which is why philosophy needs to accept it may one day be made redundant. But science also has to accept there may be limits to its reach.

Yes, there may be some things that are forever beyond the research of science (how life originated may be one such issue). But that doesn’t mean that those questions can be answered by other means, or that the limits are based on anything but our technical and perceptual abilities.

I think philosophy will always have a place in scientific discourse, although, like theology, that place will shrink as science advances. But even in the end, when we have a complete knowledge of human behavior and how it’s based on the molecular configuration of our brains interacting via our senses with the molecular configuration of our environments, philosophers will still be important for teaching us how to think hard, think logically, and figure out which questions are worth asking.

In the meantime, it would be nice if readers weighed in on the question of whether morality really is, in the end, at least partly independent of questions that can be studied via science.

But do read the Krauss/Baggini discussion: it’s one of the better things I’ve seen online in a while.