Once we see that a concern for well-being (defined as deeply and as inclusively as possible) is the only intelligible basis for morality and values, we will see that there must be a science of morality, whether or not we ever succeed in developing it: because the well-being of conscious creatures depends upon how the universe is, altogether. Given that changes in the physical universe and in our experience of it can be understood, science should increasingly enable us to answer specific moral questions. For instance, would it be better to spend our next billion dollars eradicating racism or malaria? Which is generally more harmful to our personal relationships, "white" lies or gossip? Such questions may seem impossible to get a hold of at this moment, but they may not stay that way forever. As we come to understand how human beings can best collaborate and thrive in this world, science can help us find a path leading away from the lowest depths of misery and toward the heights of happiness for the greatest number of people. Of course, there will be practical impediments to evaluating the consequences of certain actions, and different paths through life may be morally equivalent (i.e., there may be many peaks on the moral landscape), but I am arguing that there are no obstacles, in principle, to our speaking about moral truth.

  It seems to me, however, that most educated, secular people (and this includes most scientists, academics, and journalists) believe that there is no such thing as moral truth—only moral preference, moral opinion, and emotional reactions that we mistake for genuine knowledge of right and wrong. While we can understand how human beings think and behave in the name of "morality," it is widely imagined that there are no right answers to moral questions for science to discover.

  Some people maintain this view by defining "science" in exceedingly narrow terms, as though it were synonymous with mathematical modeling or immediate access to experimental data. However, this is to mistake science for a few of its tools. Science simply represents our best effort to understand what is going on in this universe, and the boundary between it and the rest of rational thought cannot always be drawn. There are many tools one must get in hand to think scientifically—ideas about cause and effect, respect for evidence and logical coherence, a dash of curiosity and intellectual honesty, the inclination to make falsi-fiable predictions, etc.—and these must be put to use long before one starts worrying about mathematical models or specific data.

  Many people are also confused about what it means to speak with scientific "objectivity" about the human condition. As the philosopher John Searle once pointed out, there are two very different senses of the terms "objective" and "subjective." 3 The first sense relates to how we know (i.e., epistemology), the second to what there is to know (i.e., ontology). When we say that we are reasoning or speaking "objectively," we generally mean that we are free of obvious bias, open to counterarguments, cognizant of the relevant facts, and so on. This is to make a claim about how we are thinking. In this sense, there is no impediment to our studying subjective (i.e., first-person) facts "objectively."

  For instance, it is true to say that I am experiencing tinnitus (ringing in my ear) at this moment. This is a subjective fact about me, but in stating this fact, I am being entirely objective: I am not lying; I am not exaggerating for effect; I am not expressing a mere preference or personal bias. I am simply stating a fact about what I am hearing at this moment. I have also been to an otologist and had the associated hearing loss in my right ear confirmed. No doubt, my experience of tinnitus must have an objective (third-person) cause that could be discovered (likely, damage to my cochlea). There is simply no question that I can speak about my tinnitus in the spirit of scientific objectivity—and, indeed, the sciences of mind are largely predicated on our being able to correlate first-person reports of subjective experience with third-person states of the brain. This is the only way to study a phenomenon like depression: the underlying brain states must be distinguished with reference to a person's subjective experience.

  However, many people seem to think that because moral facts relate to our experience (and are, therefore, ontologically "subjective"), all talk of morality must be "subjective" in the epistemological sense (i.e., biased, merely personal, etc.). This is simply untrue. I hope it is clear that when I speak about "objective" moral truths, or about the "objective" causes of human well-being, I am not denying the necessarily subjective (i.e., experiential) component of the facts under discussion. I am certainly not claiming that moral truths exist independent of the experience of conscious beings—like the Platonic Form of the Good 4 —or that certain actions are intrinsically wrong. 5 I am simply saying that, given that there are facts— real facts—to be known about how conscious creatures can experience the worst possible misery and the greatest possible well-being, it is objectively true to say that there are right and wrong answers to moral questions, whether or not we can always answer these questions in practice.

  And, as I have said, people consistently fail to distinguish between there being answers in practice and answers in principle to specific questions about the nature of reality. When thinking about the application of science to questions of human well-being, it is crucial that we not lose sight of this distinction. After all, there are countless phenomena that are subjectively real, which we can discuss objectively (i.e., honestly and rationally), but which remain impossible to describe with precision. Consider the complete set of "birthday wishes" corresponding to every conscious hope that people have entertained silently while blowing out candles on birthday cakes. Will we ever be able to retrieve these unspoken thoughts? Of course not. Many of us would be hard-pressed to recall even one of our own birthday wishes. Does this mean that these wishes never existed or that we can't make true or false statements about them? What if I were to say that every one of these wishes was phrased in Latin, focused on improvements in solar panel technology, and produced by the activity of exactly 10,000 neurons in each person's brain? Is this a vacuous assertion? No, it is quite precise and surely wrong. But only a lunatic could believe such a thing about his fellow human beings. Clearly, we can make true or false claims about human (and animal) subjectivity, and we can often evaluate these claims without having access to the facts in question. This is a perfectly reasonable, scientific, and often necessary thing to do. And yet many scientists will say that moral truths do not exist, simply because certain facts about human experience cannot be readily known, or may never be known. As I hope to show, this misunderstanding has created tremendous confusion about the relationship between human knowledge and human values.

  Another thing that makes the idea of moral truth difficult to discuss is that people often employ a double standard when thinking about consensus: most people take scientific consensus to mean that scientific truths exist, and they consider scientific controversy to be merely a sign that further work remains to be done; and yet many of these same people believe that moral controversy proves that there can be no such thing as moral truth, while moral consensus shows only that human beings often harbor the same biases. Clearly, this double standard rigs the game against a universal conception of morality. 6

  The deeper issue, however, is that truth has nothing, in principle, to do with consensus: one person can be right, and everyone else can be wrong. Consensus is a guide to discovering what is going on in the world, but that is all that it is. Its presence or absence in no way constrains what may or may not be true. 7 There are surely physical, chemical, and biological facts about which we are ignorant or mistaken. In speaking of "moral truth," I am saying that there must be facts regarding human and animal well-being about which we can also be ignorant or mistaken. In both cases, science—and rational thought generally—is the tool we can use to uncover these facts.

  And here is where the real controversy begins, for many people strongly object to my claim that morality and values relate to facts about the well-being of conscious creatures. My critics seem to think that consciousness holds no special place where values are concerned, or that any state of consciousness stands t
he same chance of being valued as any other. The most common objection to my argument is some version of the following:

  But you haven't said why the well-being of conscious beings ought to matter to us. If someone wants to torture all conscious beings to the point of madness, what is to say that he isn't just as "moral" as you are?

  While I do not think anyone sincerely believes that this kind of moral skepticism makes sense, there is no shortage of people who will press this point with a ferocity that often passes for sincerity.

  Let us begin with the fact of consciousness: I think we can know, through reason alone, that consciousness is the only intelligible domain of value. What is the alternative? I invite you to try to think of a source of value that has absolutely nothing to do with the (actual or potential) experience of conscious beings. Take a moment to think about what this would entail: whatever this alternative is, it cannot affect the experience of any creature (in this life or in any other). Put this thing in a box, and what you have in that box is—it would seem, by definition —the least interesting thing in the universe.

  So how much time should we spend worrying about such a transcendent source of value? I think the time I will spend typing this sentence is already too much. All other notions of value will bear some relationship to the actual or potential experience of conscious beings. So my claim that consciousness is the basis of human values and morality is not an arbitrary starting point. 8

  Now that we have consciousness on the table, my further claim is that the concept of "well-being" captures all that we can intelligibly value. And "morality"—whatever people's associations with this term happen to be—really relates to the intentions and behaviors that affect the well-being of conscious creatures.

  On this point, religious conceptions of moral law are often put forward as counterexamples: for when asked why it is important to follow God's law, many people will cannily say, "for its own sake." Of course, it is possible to say this, but this seems neither an honest nor a coherent claim. What if a more powerful God would punish us for eternity for following Yahweh's law? Would it then make sense to follow Yahweh's law "for its own sake"? The inescapable fact is that religious people are as eager to find happiness and to avoid misery as anyone else: many of them just happen to believe that the most important changes in conscious experience occur after death (i.e., in heaven or in hell). And while Judaism is sometimes held up as an exception—because it tends not to focus on the afterlife—the Hebrew Bible makes it absolutely clear that Jews should follow Yahweh's law out of concern for the negative consequences of notfollowing it. People who do not believe in God or an afterlife, and yet still think it important to subscribe to a religious tradition, only believe this because living this way seems to make some positive contribution to their well-being or to the well-being of others. 9

  Religious notions of morality, therefore, are not exceptions to our common concern for well-being. And all other philosophical efforts to describe morality in terms of duty, fairness, justice, or some other principle that is not explicitly tied to the well-being of conscious creatures, draw upon some conception of well-being in the end. 10

  The doubts that immediately erupt on this point invariably depend upon bizarre and restrictive notions of what the term "well-being" might mean. 11 I think there is little doubt that most of what matters to the average person—like fairness, justice, compassion, and a general awareness of terrestrial reality—will be integral to our creating a thriving global civilization and, therefore, to the greater well-being of humanity. 12 And, as I have said, there may be many different ways for individuals and communities to thrive—many peaks on the moral landscape—so if there is real diversity in how people can be deeply fulfilled in this life, such diversity can be accounted for and honored in the context of science. The concept of "well-being," like the concept of "health," is truly open for revision and discovery. Just how fulfilled is it possible for us to be, personally and collectively? What are the conditions—ranging from changes in the genome to changes in economic systems—that will produce such happiness? We simply do not know.

  But what if certain people insist that their "values" or "morality" have nothing to do with well-being? Or, more realistically, what if their conception of well-being is so idiosyncratic and circumscribed as to be hostile, in principle, to the well-being of all others? For instance, what if a man like Jeffrey Dahmer says, "The only peaks on the moral landscape that interest me are ones where I get to murder young men and have sex with their corpses." This possibility—the prospect of radically different moral commitments—is at the heart of many people's doubts about moral truth.

  Again, we should observe the double standard in place regarding the significance of consensus: those who do not share our scientific goals have no influence on scientific discourse whatsoever; but, for some reason, people who do not share our moral goals render us incapable of even speaking about moral truth. It is, perhaps, worth remembering that there are trained "scientists" who are Biblical Creationists, and their "scientific" thinking is purposed toward interpreting the data of science to fit the Book of Genesis. Such people claim to be doing "science," of course, but real scientists are free, and indeed obligated, to point out that they are misusing the term. Similarly, there are people who claim to be highly concerned about "morality" and "human values," but when we see that their beliefs cause tremendous misery, nothing need prevent us from saying that they are misusing the term "morality" or that their values are distorted. How have we convinced ourselves that, on the most important questions in human life, all views must count equally?

  Consider the Catholic Church: an organization which advertises itself as the greatest force for good and as the only true bulwark against evil in the universe. Even among non-Catholics, its doctrines are widely associated with the concepts of "morality" and "human values." However, the Vatican is an organization that excommunicates women for attempting to become priests 13 but does not excommunicate male priests for raping children. 14 It excommunicates doctors who perform abortions to save a mother's life—even if the mother is a nine-year-old girl raped by her stepfather and pregnant with twins 15 —but it did not excommunicate a single member of the Third Reich for committing genocide. Are we really obliged to consider such a diabolical inversion of priorities to be evidence of an alternative "moral" framework? No. It seems clear that the Catholic Church is as misguided in speaking about the "moral" peril of contraception, for instance, as it would be in speaking about the "physics" of Transubstantiation. In both domains, it is true to say that the Church is grotesquely confused about which things in this world are worth paying attention to.

  However, many people will continue to insist that we cannot speak about moral truth, or anchor morality to a deeper concern for well-being, because concepts like "morality" and "well-being" must be defined with reference to specific goals and other criteria—and nothing prevents people from disagreeing about these definitions. I might claim that morality is really about maximizing well-being and that well-being entails a wide range of psychological virtues and wholesome pleasures, but someone else will be free to say that morality depends upon worshipping the gods of the Aztecs and that well-being, if it matters at all, entails always having a terrified person locked in one's basement, waiting to be sacrificed.

  Of course, goals and conceptual definitions matter. But this holds for all phenomena and for every method we might use to study them. My father, for instance, has been dead for twenty-five years. What do I mean by "dead"? Do I mean "dead" with reference to specific goals? Well, if you must, yes—goals like respiration, energy metabolism, responsiveness to stimuli, etc. The definition of "life" remains, to this day, difficult to pin down. Does this mean we can't study life scientifically? No. The science of biology thrives despite such ambiguities. Again, the concept of "health" is looser still: it, too, must be defined with reference to specific goals—not suffering chronic pain, not always vomiting, etc.—and these goals are continually ch
anging. Our notion of "health" may one day be defined by goals that we can not currently entertain with a straight face (like the goal of spontaneously regenerating a lost limb). Does this mean we can't study health scientifically?

  I wonder if there is anyone on earth who would be tempted to attack the philosophical underpinnings of medicine with questions like: "What about all the people who don't share your goal of avoiding disease and early death? Who is to say that living a long life free of pain and debilitating illness is 'healthy'? What makes you think that you could convince a person suffering from fatal gangrene that he is not as healthy as you are?" And yet these are precisely the kinds of objections I face when I speak about morality in terms of human and animal well-being. Is it possible to voice such doubts in human speech? Yes. But that doesn't mean we should take them seriously.

  One of my critics put the concern this way: "Morals are relative to the time and place in which they appear. If you do not already accept well-being as a value, then there seems to be no argument for why one should promote well-being." As proof of this assertion, he observed that I would be unable to convince the Taliban that they value the wrong things. By this standard, however, the truths of science are also "relative to the time and place in which they appear," and there is no way to convince someone who does not value empirical evidence that he should value it. 16 Despite 150 years of working at it, we still can't convince a majority of Americans that evolution is a fact. Does this mean biology isn't a proper science?