I have a few simple questions for Sam Harris: Science rests on the presupposition that there are mind-independent facts to be discovered about the Universe. That is, the purpose of science is the discovery of ontological knowledge. If the distinction between mind-independent objective ontological knowledge and mind-intrinsic subjective epistemological knowledge is an illusion, and there is only the epistemic sphere, then what is science, in principle? A denial of ontological knowledge necessarily subverts one of the fundamental presuppositions that science requires to function. How can one know if there is a science of morality if one doesn’t know whether or not there is such a thing as science? And if you can’t say, then who can?
1. You have said that these essays must attack the “central argument” of your book. What do you consider that to be?
Here it is: Morality and values depend on the existence of conscious minds—and specifically on the fact that such minds can experience various forms of well-being and suffering in this universe. Conscious minds and their states are natural phenomena, fully constrained by the laws of the universe (whatever these turn out to be in the end). Therefore, questions of morality and values must have right and wrong answers that fall within the purview of science (in principle, if not in practice). Consequently, some people and cultures will be right (to a greater or lesser degree), and some will be wrong, with respect to what they deem important in life.
The meaning of “science”
Most criticisms of The Moral Landscape seem to stumble over its subtitle, “How Science Can Determine Human Values,” and I admit that this wording has become an albatross. To my surprise, many people think about science primarily in terms of academic titles, budgets, and architecture, and not in terms of the logical and empirical intuitions that allow us to form justified beliefs about the world. The point of my book was not to argue that “science” bureaucratically construed can subsume all talk about morality. My purpose was to show that moral truths exist and that they must fall (in principle, if not in practice) within some (perhaps never to be complete) understanding of the way conscious minds arise in this universe. For practical reasons, it is often necessary to draw boundaries between academic disciplines, but physicists, chemists, biologists, and psychologists rely on the same processes of thought and observation that govern all our efforts to stay in touch with reality. This larger domain of justified truth-claims is “science” in my sense.
For instance, what was the source of the Black Death that killed nearly half the population of Europe in the 14th century? It appears to have been Yersinia pestis, a bacterium that was delivered to unsuspecting people by fleabite. The fleas were transported to the Continent by rats, which were themselves carried by merchant ships. What kind of facts are these? Are they facts of nautical history, zoology, epidemiology, or medicine? Strange question. They belong to all these disciplines—and perhaps to several not yet invented. The only thing that matters is that this account of the Black Death appears to be true. (Note 6/9/14: Or perhaps it isn’t true.)
Another example, in case the point still isn’t clear:
You awaken to find water pouring through the ceiling of your bedroom. Imagining that you have a gaping hole in your roof, you immediately call the man who installed it. The roofer asks, “Is it raining where you live?” Good question. In fact, it hasn’t rained for months. Is this roofer a scientist? Not technically, but he was thinking just like one. Empiricism and logic reveal that your roof is not the problem.
So you call a plumber. Is a plumber a scientist? No more than a roofer is, but any competent plumber will generate hypotheses and test them—and his thinking will conform to the same principles of reasoning that every scientist uses. When he pressure tests a section of pipe, he is running an experiment. Would this experiment be more “scientific” if it were funded by the National Science Foundation? No. By contrast, when a world-famous geneticist like Francis Collins declares that the biblical God installed immortal souls, free will, and morality in one species of primate, he is repudiating the core values of science with every word. Drawing the line between science and non-science by reference to a person’s occupation is just too crude to be useful—but it is what many of my critics seem to do.
I am, in essence, defending the unity of knowledge—the idea that the boundaries between disciplines are mere conventions and that we inhabit a single epistemic sphere in which to form true beliefs about the world. This remains a controversial thesis, and it is generally met with charges of “scientism.” Sometimes, the unity of knowledge is very easy to see: Is there really a boundary between the truths of physics and those of biology? No. And yet it is practical, even necessary, to treat these disciplines separately most of the time. In this sense, the boundaries between disciplines are analogous to political borders drawn on maps. Is there really a difference between California and Arizona at their shared border? No, but we divide this stretch of desert as a matter of convention. However, once we begin talking about non-contiguous disciplines—physics and sociology, say—people worry that a single, consilient idea of truth can’t span the distance. Suddenly, the different colors on the map look hugely significant. But I’m convinced that this is an illusion.