Enlightenment Now

  But theistic morality has two fatal flaws. The first is that there is no good reason to believe that God exists. In a nonfiction appendix to her novel Thirty-Six Arguments for the Existence of God: A Work of Fiction, Rebecca Newberger Goldstein (drawing in part on Plato, Spinoza, Hume, Kant, and Russell) lays out refutations of every one of these arguments.32 The most common among them—faith, revelation, scripture, authority, tradition, and subjective appeal—are not arguments at all. It’s not just that reason says they cannot be trusted. It’s also that different religions, drawing on these sources, decree mutually incompatible beliefs about how many gods there are, which miracles they have wrought, and what they demand of their devotees. Historical scholarship has amply demonstrated that holy scriptures are all-too-human products of their historical eras, including internal contradictions, factual errors, plagiarism from neighboring civilizations, and scientific absurdities (such as God creating the sun three days after he distinguished day from night). The recondite arguments from sophisticated theologians are no sounder. The Cosmological and Ontological arguments for the existence of God are logically invalid, the Argument from Design was refuted by Darwin, and the others are either patently false (such as the theory that humans are endowed with an innate faculty for sensing the truth about God) or blatant escape hatches (such as the suggestion that the Resurrection was too cosmically important for God to have allowed it to be empirically verified).

  Some writers insist that science has no place in this conversation. They seek to impose a condition of “methodological naturalism” on science which renders it incapable, even in principle, of evaluating the claims of religion. That would carve out a safe space in which believers can protect their beliefs while still being sympathetic to science. But as we saw in the preceding chapter, science is not a game with an arbitrary rulebook; it’s the application of reason to explaining the universe and to ascertaining whether its explanations are true. In Faith Versus Fact, the biologist Jerry Coyne argues that the existence of the God of scripture is a perfectly testable scientific hypothesis.33 The Bible’s historical accounts could have been corroborated by archaeology, genetics, and philology. It could have contained uncannily prescient scientific truths such as “Thou shalt not travel faster than light” or “Two strands entwined is the secret of life.” A bright light might appear in the heavens one day and a man clad in a white robe and sandals, supported by winged angels, could descend from the sky, give sight to the blind, and resurrect the dead. We might discover that intercessory prayer can restore eyesight or regrow amputated limbs, or that anyone who speaks the Prophet Mohammed’s name in vain is immediately struck down while those who pray to Allah five times a day are free from disease and misfortune. More generally, the data might show that good things happen to good people and bad things happen to bad people: that the mothers who die in childbirth, the children who waste away from cancer, and the millions of victims of earthquakes, tsunamis, and holocausts had it coming.

  Other components of theistic morality, such as the existence of an immaterial soul and a realm of reality beyond matter and energy, are just as testable. We might discover a severed head that can speak. A seer could predict the exact day of natural disasters and terrorist attacks. Aunt Hilda could beam a message from the Great Beyond telling us under which floorboard she hid her jewelry. Memoirs from oxygen-starved patients who experienced their souls leaving their bodies could contain verifiable details unavailable to their sense organs. The fact that these reports have all been exposed as tall tales, false memories, overinterpreted coincidences, and cheap carny tricks undermines the hypothesis that there are immaterial souls which could be subject to divine justice.34 There are, of course, deistic philosophies in which God created the universe and then stepped back to watch what happened, or in which “God” is merely a synonym for the laws of physics and mathematics. But these impotent Gods are in no position to underwrite morality.

  * * *

  Many theistic beliefs originated as hypotheses to explain natural phenomena such as the weather, disease, and the origin of species. As these hypotheses have been superseded by scientific ones, the scope of theism has steadily shrunk. But since our scientific understanding is never complete, the pseudo-argument known as the God of the Gaps is always available as a last resort. Today the more sophisticated theists have tried to place God into two of these gaps: the fundamental physical constants and the hard problem of consciousness. Any humanist who insists that we cannot invoke God to justify morality can expect to be confronted with these gaps, so let me say a few words about each. As we will see, they are likely to go the way of Zeus hurling thunderbolts as an explanation for electrical storms.

  Our universe can be specified by a few numbers, including the strengths of the forces of nature (gravity, electromagnetism, and the nuclear forces), the number of macroscopic dimensions of space-time (four), and the density of dark energy (the source of the acceleration of the expansion of the universe). In Just Six Numbers, Martin Rees enumerates them on one hand and a finger; the exact tally depends on which version of physical theory one invokes and on whether one counts the constants themselves or ratios between them. If any of these constants were off by a minuscule iota, then matter would fly apart or collapse upon itself, and stars, galaxies, and planets, to say nothing of terrestrial life and Homo sapiens, could never have formed. The best-established theories of physics today don’t explain why these constants should be so meticulously tuned to values that allowed us to come into being (particularly the density of dark energy), and so, the theistic argument goes, there must have been a fine-tuner, namely God. It is the old Argument from Design applied to the entire cosmos rather than to living things.

  An immediate objection is the equally old problem of theodicy. If God, in his infinite power and knowledge, fine-tuned the universe to bring us into being, why did he design an Earth on which geological and meteorological catastrophes devastate regions inhabited by innocent people? What is the divine purpose of the supervolcanoes that have ravaged our species in the past and may extinguish it in the future, or the evolution of the Sun into a red giant that will do so with certainty?

  But theodical speculation is beside the point. Physicists have not been left dumbstruck by the apparent fine-tuning of the fundamental constants, but are actively pursuing several explanations. One is captured in the title of the physicist Victor Stenger’s book The Fallacy of Fine-Tuning.35 Many physicists believe that it’s premature to conclude that the values of the fundamental constants are either arbitrary or the only ones consistent with life. A deeper understanding of physics (particularly the long-sought unification of relativity and quantum theory) may show that some of the values must be exactly what they are. Others, we might learn, could take on other values—more important, combinations of values—that are compatible with a stable, matter-filled universe, albeit not the one we know and love. Progress in physics may reveal that the constants are not so finely tuned, and a life-supporting universe not so improbable, after all.

  The other explanation is that our universe is just one region in a vast, possibly infinite landscape of universes—a multiverse—each with different values of the fundamental constants.36 We find ourselves in a universe compatible with life not because it was tuned to allow us to exist but because the very fact that we exist implies that it is that kind of universe, and not one of the vastly more numerous inhospitable ones, that we find ourselves in. Fine-tuning is a fallacy of post hoc reasoning, like the Megabucks winner who wonders what made him win against all odds. Someone had to win, and it’s only because it happened to be him that he’s wondering in the first place. It’s not the first time that a selection artifact has fooled thinkers into searching for a nonexistent deep explanation for a physical constant. Johannes Kepler agonized over why the Earth was 93 million miles away from the sun, just right for water to fill our lakes and rivers without freezing solid or boiling away. Today we know that the Earth is just one of ma
ny planets, each at a different distance from our sun or another star, and we are unsurprised to learn that we find ourselves on that planet rather than on Mars.

  The theory of the multiverse would itself be a post hoc excuse for an explanation if it were not consistent with other theories in physics—in particular, that the vacuum of space can spawn big bangs which grow into new universes, and that the baby universes can be born with different fundamental constants.37 Still, the very idea repels many people (not least some physicists) because of its mind-boggling profligacy. An infinity of universes (or at least a number large enough to include all possible arrangements of matter) implies that somewhere there are universes with exact doppelgangers of you except that they married someone else, were killed by a car last night, are named Evelyn, have one hair out of place, put the book down a moment ago and are not reading this sentence, and so on.

  Yet however unsettling these implications are, the history of ideas tells us that cognitive queasiness is a poor guide to reality. Our best science has repeatedly insulted our ancestors’ common sense with unsettling discoveries that turned out to be true, including a round Earth, a slowdown of time at high speeds, quantum superposition, curved space-time, and of course evolution. Indeed, once we get over the initial shock, we find that a multiverse is not so exotic after all. This is not even the first time that physicists have had a reason to posit multiple universes. Another version of the multiverse is a straightforward implication of the discoveries that space appears to be infinite and that matter appears to be evenly dispersed through it: there must be an infinity of universes dotting 3-D space beyond our cosmic horizon. Still another is the many-worlds interpretation of quantum mechanics, in which the multiple outcomes of a probabilistic quantum process (such as the trajectory of a photon) are all realized in superimposed parallel universes (a possibility that could lead to quantum computers, in which all possible values of the variables in a computation are represented simultaneously). Indeed, in one sense the multiverse is the simpler theory of reality, since if our universe is the only one in existence, we would need to complicate the elegant laws of physics with an arbitrary stipulation of our universe’s parochial initial conditions and its parochial physical constants. As the physicist Max Tegmark (an advocate of four kinds of multiverse) put it, “Our judgment therefore comes down to which we find more wasteful and inelegant: many worlds or many words.”

  If the multiverse turns out to be the best explanation of the fundamental physical constants, it would not be the first time we have been flabbergasted by worlds beyond our noses. Our ancestors had to swallow the discovery of the Western Hemisphere, eight other planets, a hundred billion stars in our galaxy (many with planets), and a hundred billion galaxies in the observable universe. If reason contradicts intuition once again, so much the worse for intuition. Another advocate of the multiverse, Brian Greene, reminds us:

  From a quaint, small, earth-centered universe to one filled with billions of galaxies, the journey has been both thrilling and humbling. We’ve been compelled to relinquish sacred belief in our own centrality, but with such cosmic demotion we’ve demonstrated the capacity of the human intellect to reach far beyond the confines of ordinary experience to reveal extraordinary truth.38

  * * *

  The other supposedly God-fillable gap is the “hard problem of consciousness,” also known as the problem of sentience, subjectivity, phenomenal consciousness, and qualia (the “qualitative” aspect of consciousness).39 The term, originally suggested by the philosopher David Chalmers, is an in-joke, because the so-called easy problem—the scientific challenge of distinguishing conscious from unconscious mental computation, identifying its substrates in the brain, and explaining why it evolved—is “easy” in the sense that curing cancer or sending a man to the Moon is easy, namely that it is scientifically tractable. Fortunately, the easy problem is more than just tractable: we are well on the way to a satisfying explanation. It’s hardly a mystery why we experience a world of stable, solid, colored 3-D objects rather than the kaleidoscope of pixels on our retinas, or why we enjoy (and hence seek) food, sex, and bodily integrity while suffering from (and hence avoiding) social isolation and tissue damage: these internal states and the behavior they encourage are obvious Darwinian adaptations. With advances in evolutionary psychology, more and more of our conscious experiences are being explained in this way, including our intellectual obsessions, moral emotions, and aesthetic reactions.40

  Nor are the computational and neurobiological bases of consciousness obstinately befuddling. The cognitive neuroscientist Stanislas Dehaene and his collaborators have argued that consciousness functions as a “global workspace” or “blackboard” representation.41 The blackboard metaphor refers to the way that a diverse set of computational modules can post their results in a common format that all the other modules can “see.” Those modules include perception, memory, motivation, language understanding, and action planning, and the fact that they can all access a common pool of currently relevant information (the contents of consciousness) allows us to describe, grasp, or approach what we see, to respond to what other people say or do, and to remember and plan depending on what we want and what we know. (The computations inside each module, in contrast, like the calculation of depth from the two eyes or the sequencing of muscle contractions making up an action, can work off their own proprietary input streams, and they proceed below the level of consciousness, having no need for its synoptic view.) This global workspace is implemented in the brain as rhythmic, synchronized firing in neural networks that link the prefrontal and parietal cerebral cortexes with each other and with brain areas that feed them perceptual, mnemonic, and motivational signals.

  The so-called hard problem—why it subjectively feels like something to each one of us who is conscious, with red looking red and salt tasting salty—is hard not because it is a recalcitrant scientific topic but because it is a head-scratching conceptual enigma. It includes brainteasers such as whether my red is the same as your red, what it is like to be a bat, whether there could be zombies (people indistinguishable from you and me but with “no one home” who is feeling anything), and if so whether everyone but me is a zombie, whether a perfectly lifelike robot would be conscious, whether I could achieve immortality by uploading my brain’s connectome to the Cloud, and whether the Star Trek transporter really transports Captain Kirk to the planetary surface or murders him and reconstitutes a twin.

  Some philosophers, like Daniel Dennett in Consciousness Explained, have argued that there is no hard problem of consciousness: it is a confusion arising from the bad habit of imagining a homunculus seated in a theater inside the skull. This is the disembodied experiencer who would temporarily tiptoe out of my theater and drop in on yours to check out the red, or visit the bat’s and watch the movie that’s playing there; who would be missing from the zombie and either present or absent in the robot; and who might or might not survive the beam ride down to Zakdorn. Sometimes, when I see the mischief that the hard problem has caused (including the conservative intellectual Dinesh D’Souza brandishing a copy of my book How the Mind Works in a debate on the existence of God), I am tempted to agree with Dennett that we’d be better off without the term. Contrary to various misunderstandings, the hard problem does not consist in weird physical or paranormal phenomena such as clairvoyance, telepathy, time travel, augury, or action at a distance. It does not call for exotic quantum physics, kitschy energy vibrations, or other New Age flimflam. Most important for the present discussion, it does not implicate an immaterial soul. Nothing that we know about consciousness is inconsistent with the understanding that it depends entirely on neural activity.

  In the end I still think that the hard problem is a meaningful conceptual problem, but agree with Dennett that it is not a meaningful scientific problem.42 No one will ever get a grant to study whether you are a zombie or whether the same Captain Kirk walks on the deck of the Enterprise and the surface of Zakdor
n. And I agree with several other philosophers that it may be futile to hope for a solution at all, precisely because it is a conceptual problem, or, more accurately, a problem with our concepts. As Thomas Nagel put it in his famous essay “What Is It Like to Be a Bat?” there may be “facts which could not ever be represented or comprehended by human beings, even if the species lasted forever—simply because our structure does not permit us to operate with concepts of the requisite type.”43 The philosopher Colin McGinn has run with this idea, arguing that there is a mismatch between our cognitive tools for explaining reality (namely chains of causes and effects, analysis into parts and their interactions, and modeling in mathematical equations) and the nature of the hard problem of consciousness, which is unintuitively holistic.44 Our best science tells us that consciousness consists of a global workspace representing our current goals, memories, and surroundings, implemented in synchronized neural firing in fronto-parietal circuitry. But the last dollop in the theory—that it subjectively feels like something to be such circuitry—may have to be stipulated as a fact about reality where explanation stops. This should not be entirely surprising. As Ambrose Bierce noted in The Devil’s Dictionary, the mind has nothing but itself to know itself with, and it may never feel satisfied that it understands the deepest aspect of its own existence, its intrinsic subjectivity.