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God in Proof The Story of a Search from the Ancients to the Internet

  • by Nathan Schneider (Author)
  • July 2015
  • First Edition
  • Paperback
  • Title Details

    Rights: Incl. US and Territ, Canada, Philippines
    Pages: 272
    ISBN: 9780520287464
    Trim Size: 6 x 9
    Illustrations: 30 line illustrations, 5 tables

Read Chapter 1


First Causes

Ancient times and reasonable measures

The first time I remember thinking about proofs for the existence of God was when I was seventeen, thanks to a book I came across at my friend Corinne's house. It was muddy green and fairly large-an encyclopedic, spirited compendium of things about which one should know. The proofs took up no more than a couple of pages, and they weren't cast in an especially favorable light. They were more like a centuries-old joke, actually, a joke that one should be prepared for just in case anyone ever tries passing them off as anything other than that. One should be ready for the punch line.

The book listed and summarized three proofs, each hiding behind impressive names: ontological, cosmological, teleological-having to do with being, world, and purpose. I instantly became attached to it and went about dropping hints to Corinne that it would the perfect present for my upcoming birthday. But the message didn't seem to get through. Why would it? How could she guess what effect it was having on me? How could she know what those proofs felt like in my head? I really had to spell out what this meant to me.

I had spent my childhood watching my parents as they did their own experiments with, if not proof, truth. As they went about the business of seeking, I followed, tiptoeing through rooms full of meditators and testing my aptitude-low, it turns out-for extrasensory perception. My mother, especially, sought out teachers and books, and there was an ongoing procession of diet regimes. These experiments could involve some reference to God, but it was a God of the vaguest sort, whose name my parents were sure to pass over quickly so as not to confuse it with the Jewish and Christian deities that they had learned, and disavowed, before I was born.

The premise from the start was that I should choose what to believe about religious things, since they were still choosing for themselves. For an only child this was bound to be a lonely task, but I took to it early on. I would ask to go to synagogue with friends, and deploy parables of the Buddha during hts on the playground. One can only experiment so much though. "There are years that ask questions," Zora Neale Hurston wrote in passing, "and years that answer." By the time Corinne's book came around, a need was gnawing in me for answers, and no answer seemed more satisfying than a proof.

Philosophy, when it takes hold of a teenager, means taking oneself very seriously on matters of gross incompetence. There are no minor leagues, no lower gears; one goes straight from zero to everything in no time, and the most alluring stuff is exactly the most fundamental and the most lofty, just when one is least prepared to take any of it with a grain of salt. Even so, and consequently, there's no better time than adolescence to fall in love with philosophy, or to develop an intellectual dependency on it, for neither love nor addiction occurs when one is being sensible. They thrive on heroic feats of self-delusion and clever rationalization, and so does philosophy.

Causes, though, can be a trickster. What causes what? How and why? What really caused me to care about these proofs so much, and where did the proofs come from in the first place? Talking about the cause of anything is harder than you might think.

It's conventional, in this case, to start with the Greeks. I wish I could do otherwise, for originality's sake. But while those -ological terms I came across were a later invention, their etymology is Greek, and for good reason. Without exactly meaning to, the ancient Greeks were the ones who caused the whole story of proofs to happen, or at least to happen the way it did.

The kind of Greek religion I had been briefly obsessed with in fifth grade had no place for proofs-the myths, the temples, the heroes, the cavorting. People had reasons for believing in the gods of Mount Olympus other than proofs. Homer's verses of deities and warrior-kings uniting in the siege against Troy reminded the disparate Greek city-states of what they had in common. Hesiod's tales told lessons about morality and economy, together with answers to questions about the universe, and one could repeat them to seduce a lover or to scold a misbehaving child. The public sacrifices made to these gods were carefully orchestrated affairs, and the role one played in them reflected one's position in society. The gods were real-or else. And while public ritual served politics and epic myths made for literature, so-called mystery cults allowed people to go deeper. There were illustrations in the books I read as a kid of people gathered in caves or dark rooms, conducting rituals and repeating secret doctrines said to have been conferred by a patron god. These mystery cults provided transformative experiences. Through them, ancient Greeks knew that esoteric knowledge can have spiritual power.

Then, around the middle of the first millennium B.C.E., a new batch of sages, students, and charlatans appeared, many from the Greek colonies across the Mediterranean. They converged at Athens, calling themselves philosophers-lovers of wisdom. Rather than ritual, voice, and memory, their tools were prose, writing, and reason. Instead of glorifying the human body, as Olympian religion did, the body became a prison for the thinking soul to escape. Their method was logos, a term with meanings as diverse as those who used it: word, reason, logic, mind. They departed from the capricious gods and the rituals of popular religion, but they shared the mystery cults' appetite for powerful knowledge and the poets' willingness to dream up stories about invisible things. They made myths of their own out of proofs.

One of the first proofs most of us encounter in school is that for the Pythagorean theorem, which deals with the lengths of the sides on a right triangle. It is as good a place to start as any; proofs of a God will come soon enough. Pythagoras of Samos probably didn't discover the theorem that bears his name, though he and his followers certainly studied it. The legend goes that after fleeing his home island of Samos in the Aegean, Pythagoras had a restless youth, studying with Egyptian masters and being taken as a prisoner to Babylon. Both civilizations had sophisticated mathematics to support their architectural ambitions, so young Pythagoras learned from the best. He encountered ideas from as far away as South and East Asia. Then he finally settled in the Greek colonies of southern Italy and gained a following. The ancient sources don't give a consistent account of what exactly he believed, but they show clearly enough that he reveled in a world of majestic comprehensibility, plus a fair amount of strangeness.

He preached, for instance, the transmigration of souls-that people's spirits could be reincarnated in the bodies of animals. To avoid harming their ancestors, therefore, Pythagoreans wouldn't eat meat or beat a disobedient dog. Like the Zoroastrians in Persia, they believed that the world is locked in a contest between light and darkness, good and evil. Pythagorean communities were the monasteries of the ancient world, holding property in common and living by a rigid code. Several centuries after Pythagoras, Iamblichus of Chalcis wrote, "The aim of all the Pythagorean precision about what should and should not be done is association with the divine. This is their starting-point, and their way of life has been wholly organized with a view to following God." To them, the evil in the world was the imprecise and the uncertain, which is why math was so important. Again, Iamblichus: "The Pythagoreans devoted themselves to mathematics and admired the accuracy of its reasonings, because it alone among human activities knows of proofs."

Most mathematical proofs in those days took form in pictures of abstract shapes; the algebraic notation we use now wasn't invented yet. The Pythagoreans considered these pictures sacred, combining geometry and mystery cult in a single scientific-religious mélange. The correspondence between mathematical ratios and musical scales especially fascinated Pythagoras. He believed that the movements of the stars and planets make a beautiful sound, playing always, which we don't notice only because we've been hearing it our entire lives.

The idea of mixing mathematics with mythology seems odd to us today. We memorize formulas, use them to do problem sets, and forget most of it when the test is over. But that's not the way mathematics was, and continues to be, created. It's a foray into the unknown that borders on mysticism. Polls suggest that among scientists mathematicians are most likely to believe in a God. Maybe spending one's life immersed in abstractions makes a divine mind seem more plausible. But I wouldn't really be one to know.

Math didn't come easily to me growing up. My father did his best to help. For a time in middle school, I would wake up each morning and find waiting for me a paper with a set of problems in his delicate, hieroglyphic handwriting. But math problems were the last thing I wanted to do in my first waking minutes, and downstairs I would hand them to him with dashed-off answers, if any.

Dad was a real estate agent-of heroic ability, as his clients have always told me. Work kept him out late, and he would eventually come in the front door with a pile of papers in his arms, topped by a clunky old HP-12C calculator. His mind seemed like a calculator too. Given a date, he could instantly say how old somebody was at the time; given a price, he would produce the tax or interest as if by reflex. He always counted steps as he walked up and down them, automatically and insuppressibly. If it weren't for him telling me that each flight in our house had eight steps, on dark nights I would have been content to feel each with my sock to tell if it was the last.

A hobby of Dad's was to make family trees of English royalty with his computer. They became dot-matrix murals that covered the long wall of his study. He had traveled to castles and cathedrals, and he would tell wonderful stories about them over dinner if something got him started. We had no blood of Stuarts or Hanovers or Windsors ourselves, of course, but they became a sort of extended family.

As I was getting ready for bed, I might hear him singing part of a Verdi aria, accompanying himself on the piano, and after he went silent, if I crept out of bed, I would see him lying on the couch with headphones on. Maybe this time it was Wagner, or Puccini. On other nights he would ramble around the backyard in the dark, planning the next part of his garden.

In high school geometry, math finally started to become something I could wrap my mind around; we started learning about proofs. We learned how to construct arguments from basic principles. All of a sudden math class was not simply a matter of calculating, but of discovering, and my attitude about it changed entirely. I took calculus my senior year and felt the exhilaration of late-night group study sessions, when the solution to a problem would finally come loose for us after hours of tugging at it from every direction. We learned to derive important theorems, masterpieces that had been composed in great minds of centuries past, and then used those theorems to derive more. In physics class, we used the math to predict the motion of tangible objects. I worked my way twice through a floppy paperback of Einstein's Relativity. Like the correspondence Pythagoreans found between mathematics and musical scales, Einstein's equations declared that the universe is not what it seems.

Around the time Pythagoras died, at the beginning of the fifth century B.C.E., another Greek thinker of strange notions and lasting influence was born, also in southern Italy. Like Pythagoras, Parmenides of Elea treaded in the brackish region between religion and philosophy, myth and logos,and politics. The laws he established in Elea survived him by five hundred years. He wrote his treatise in the form of a poem, though its verses strain to accommodate their meticulousness. They seem ready to burst into prose at any moment. As did the epic poets, he attributed his inspiration to the whispers of a goddess who opened his eyes and moved his pen. But like the philosophers he strove to make no claim without reasons.

The goddess guided him to divide his poem into two parts: the Way of Truth and the Way of Appearance. The second is a compendium of what he takes to be false opinions that people have about the world; it resembles Pythagoreanism. The first is an all-out attack on common sense, in the name of banishing logical contradiction. Nothing, Parmenides claims, cannot exist. Everything conceivable exists, unchangeably, eternally, in perfect unity, and in the shape of a sphere. What we see in the world that appears to change, to cease to exist, and to differ from other things is all illusion. That anything could not exist is a contradiction; if you conceive of a thing not existing, it then exists in the very conception. In this weird way, the goddess gets him to trust his mind before his eyes. Thoughts are the reality of the world, and logic is its native language.

Among his fellow Greek sages, such totalizing notions were commonplace. Thales claimed that everything is really water, Anaximenes said everything is air, and Heraclitus answered that everything is like an ever-burning fire. Parmenides was different; a century and a half later, a commentator named Eudemus wrote, "Parmenides would not agree with anything unless it seemed necessary, whereas his predecessors used to come up with unsubstantiated assertions."

Human minds make imperfect looms for pure reason. Even when such careful thinking doesn't turn into an affront to the obvious, as it did for him, it gets tangled up often enough. Philosophy, for me, started to be of interest after forcing myself to go cold turkey on a years-long obsession with Star Trek and the show's vision of a future made better by human reason.Yet the words of Spock to a precocious younger Vulcan in Star Trek VI seem apropos here: "Logic is the beginning of wisdom, Valeris, not the end." Behind them, in Spock's quarters, hung a Marc Chagall painting of Adam and Eve's expulsion from Paradise.

A hundred years after Parmenides, in the early fourth century B.C.E., the young Plato arrived in Syracuse, Sicily. Athens had only recently executed Socrates, his obstreperous mentor, and Plato had already earned a reputation as a sage in his own right. In Syracuse, he began what would be a decades-long entanglement with the royal court in an attempt to test his ideas in practice, to put philosophy in charge of a whole society. There, he came into contact with followers of Pythagoras and Parmenides, who lived not far away, on the boot of Italy, and kneaded their philosophies into his own. If there's any doubt about the place of abstract reason, of logos, in Plato's mind, one need only recall the sign over the door to the Academy he founded, just outside the walls of Athens: LET NO ONE IGNORANT OF GEOMETRY ENTER.

Plato, like his predecessors, taught that genuine Truth and Reason-capital T and capital R-aren't to be found in the visible world. Instead, he believed there are higher "forms," or "ideas": eternal, unchanging, and perfect molds from which the stuff that surrounds us is cast. The Timaeus, a dialogue written forty years after his teacher's death, is Plato's most ambitious effort to explain the nature of the universe. And there is a proof in it for the semblance of a God, culled from habits of mind he learned in Italy and in the Athenian agora.

Look around. Everything in the world is always changing and becoming. Then, look inside your mind, to mathematics, logic, shapes, abstractions. These never change. They're among the ideal forms, fixed inalterably in the universe's structure. Among the temporal and the passing, notice something else: everything must have a cause. If it exists, and once did not exist, it was created somehow. The dialogue's main speaker, after whom the Timaeus is named, surmises that there must be a divine creator who makes the world according to a blueprint of preexisting forms. He calls this creator dēmiourgos, meaning "craftsman" or "common worker," but its nature and identity remain mostly a mystery: "The father and maker of all this universe is past finding out; and even if we found him, to tell of him to all men would be impossible." If anything can be learned about the creator, it will be through esoteric proofs, accessible only to philosophers.

I learned about Plato's forms from my first philosophy teacher, Ken Knisley, a taxi driver who occasionally taught elective classes at my high school. He had untamable curly hair and a matching beard, ringed with the beads of sweat brought on by his full-body gestures. He also had a show on community access TV, on which he wore a navy blue jumpsuit that said PHILOSOPHER on the breast-except when he wore a toga to act out Plato's famous cave allegory.

We all live, says Plato, as if we're prisoners in a cave. There is a fire at our backs, casting the shadows of objects on the wall before us. Truth is something we're unaccustomed to seeing; we see just shadows. Visible, transitory things are reflections of an invisible reality.

What, then, would happen if a prisoner of the cave escaped and climbed up into the sunlight? There, he finds an entirely new kind of light, blinding him at first. With time, though, the prisoner looks up from the shadows and objects and reflections to the sun itself: "He will contemplate him"-this sun god-"as he is."

He will then proceed to argue that this is he who gives the season and the years, and is the guardian of all that is in the visible world, and in a certain way the cause of all things which he and his fellows have been accustomed to behold.

That sun stands for the Good, the highest of the forms, whose light shines on everything that is True, with a capital T.

It was in Ken's classes that I first felt the tug of exalted ideas. We read philosophers supposedly too difficult for us, and he pushed us to give an account of ourselves in terms of them. Some days, he would forget the assigned text entirely and, in amazement, tell us stories about his toddler son. He taught the pleasure and the payoff of thinking, and the responsibility each of us has to seek out undying truth. The upshot: I had a job to do, to ure out the universe for myself.

The philosophy that Ken offered was one of meaning in the face of meaninglessness. Instead of biblical salvation, we learned about Greek drinking parties and German angst. Mention of God would sneak into our discussions only because of how the existentialists mourned God's death. These readings certainly suited my emotional state. For one homework assignment, I composed a distortion-drenched, power-chord song on my guitar to accompany a passage from Nietzsche's Thus Spoke Zarathustra. When I put my recording in the cassette player, Ken leaped to the front of the room and started reciting the text with appropriate vigor: "One must have chaos within oneself to give birth to a dancing star!"

Some years later, I learned that Ken had died of cancer without much warning. Later still, I came across a makeshift online eulogy, tacked to the comments of a blog he had started in his last days. A friend of his captured a bit of Plato's eternal forms when she wrote there, "Some conversations, some ideas, really deserve to continue, even when the person who started them ... ends." The shadows of human life pass away, but the ideas that we wrestle with never do. Ken would have liked that. But he also refused the consolation of pure ideas. He titled the blog's first and only post "No Abstraction."

Plato may have looked to ideas beyond, too, but he did so in this-worldly ways. He wrote down his philosophy in dialogues, conversations among people seeking after truths together. For him philosophizing was inseparable from the love between fellow seekers, between student and teacher, and among friends. Through discussion, one's soul investigates itself. It thinks about thinking. By reaching for eternal ideas, beyond the cave of the material world, human souls can touch divinity. A conversation among philosophers is a council of gods. That was another thing I learned first from Ken: the pleasure of philosophy when done with others. He taught us what was in books, but he also made us his friends. The off-topic talk about his son was on-topic after all.

Near the end of his life, Plato lost faith in the utopian projects that had brought him to Sicily; the Syracusan kings turned out to be irredeemable tyrants. His final, unfinished book, the Laws, describes a city that would be "second best" to perfection, though more realistic in practice. Socrates, who appears in most of Plato's dialogues, is absent in the Laws. It's noticeable, and unsettling, as if Plato felt that the teacher of his youth-capitally punished on the charge of impiety-might disapprove.

While his earlier books tended to handle the traditional gods ambiguously, even playfully, here they have a very serious job to do. Plato tells us, in chapter 10 of the Laws, that the root of all crime in society is disbelief in the existence, attention, or integrity of the gods. It's that simple. "No one who in obedience to the laws believed that there were gods," he writes, "ever intentionally did any unholy act, or uttered any unlawful word." Lawbreakers, therefore, should endure not only regular punishment for their crimes; they must also listen to lectures containing proofs of the existence and significance of the gods. One of the first recorded instances of proof for divine beings, it seems, is as a correctional device.

Speaking on behalf of civic order, Plato's Athenian Stranger sounds tired and impatient. He complains, "Who can be calm when he is called upon to prove the existence of the gods? Who can avoid hating and abhorring the men who are and have been the cause of this argument?" He complains about the impertinence of these common criminals "who will not believe the tales which they have heard as babes and sucklings from their mothers and nurses," and who therefore must be subjected to philosophy. Still, Plato allows, "the attempt must be made."

His first two arguments for the existence of the gods are terse and hurried; the first is from the order of the natural world, and the second is from the fact that people of all cultures seem to be in general agreement.

In the first place, the earth and the sun, and the stars and the universe, and the fair order of the seasons, and the division of them into years and months, furnish proofs of their existence; and also there is the fact that all Hellenes and barbarians believe in them.

Later on, the Athenian Stranger unveils a more detailed argument, which relies on the nature of motion.

There are ten kinds of motion, he explains, but only one, the motion of a living soul, doesn't depend on being moved by something else. A soul-the soul of an immaterial god-must therefore have been the first motion of all. (Actually, there must be at least two such souls: one causing good order and another causing erratic evil.) "And judging from what has been said," Plato concludes, "there would be impiety in asserting that any but the most perfect soul or souls carries round the heavens." These souls, as human souls must, obey the eternal laws of the universe-which include the laws of the city. When you believe in such gods, you can't help but believe in the city's laws too.

For the earlier Plato, arguments about the gods were a matter of pleasurable, rational speculation, a conversation among philosophers. Here, proofs are servants to the social order. But the underlying idea is the same: pure reason is what rules the world, not the whims of an Olympian soap opera. As FrederickCopleston puts it in his canonical history of philosophy, "'Atheist' means for Plato, first and foremost, the man who denies the operation of Reason in the world." It is a definition that might rub many actual atheists nowadays the wrong way. What's more, in the eyes of his own society, it was Plato who could seem like an atheist for exchanging the meddlesome gods of the poets for law-abiding, reasonable ones. But others, in the centuries to come, would conclude he must have had inspiration from above.

When I was in middle school, my parents decided that we should begin taking family trips to Europe. Planned summer activities were unfortunately a doomed proposition where I was concerned; I hated every summer camp I was ever sent to, and being stuck with my parents, together with whichever grandparents could come along, was sure to bring out the brat in me, and it did.

Each trip had some special significance. Paris, for one, gave my mother a chance to revisit the years she had spent in France studying medieval French epics. Germany, I found when we got there, was my father's turn. He had taken German as a student and spent a summer hunting down in situ altarpieces by the medieval sculptor Tilman Riemenschneider. (He was able to show me why, at a fortuitous exhibition in Munich: faces with joy disguised in melancholy.) His choice to go there, and to learn that language, was especially rebellious for someone coming from a post-Holocaust Jewish family, as he did, that avoided buying German-made things.

The idea of a trip to Italy came from my father's mother, but a last-minute medical mishap prevented her from coming. In Florence, Venice, and Rome, we did what you would expect; we went to a lot of museums and churches. The churches were especially a problem because there was one around every corner, and it was hard (for everyone but me) to resist going inside. It turned out, though, that my parents were really good at visiting churches. They stayed away from the tour groups and found some piece of art that even I would have to admit was interesting, especially when one of them explained it to me. They were still always too slow. But even through my boredom I got the message: Something about this is important.

The day in Italy I have the hardest time forgetting was when we went to Vatican City, mainly because of its unpleasantness. The crowds were overwhelming-thousands of people from who-knows-where who mostly only care to see the Sistine Chapel, yet have to soldier through nearly the entire Vatican Museums on the way. Until, that is, they find something that catches them, something they've seen in books a million times and are pleased and surprised-once they push through the huddle of others around it-to encounter the real thing. One of those is relevant here. It's Raphael's fresco The School of Athens, on the wall behind you and to the left, as I recall, when you enter the Apostolic Palace's Room of the Segnatura.

Among the many heroes of ancient thought that the fresco gathers under marble arches, Plato and Aristotle stand at the center. They are side by side, with the younger Aristotle slightly to the fore of white-bearded Plato. They speak with their gestures. Plato holds the Timaeus to his body and points his right index finger to the sky. Aristotle, who was once Plato's student, looks back at the master and, balancing his Ethics outward against his thigh, holds the palm of his hand toward the earth.

This is the standard caricature of the two prototypical philosophers: Plato sought truth and order in the utopian clouds, while Aristotle cataloged marine life on the shores of the Aegean. For both, however, the cosmos is basically rational, mathematical, teachable, and learnable. They preferred clear argumentation to epic poetry and believed in a truth higher than the gods of temples and legends. The job of their philosophy was to seek after that truth, that universal reason. They had no scripture, bishops, or savior, yet still their God would land them in the heart of the popes' palace centuries after they had died.

The foundation of Aristotle's philosophy is the system of logic that, for almost two thousand years, provided Europe with its definition of reason. His best-known principle is the syllogism, the basic unit of deduction and proof, whereby a conclusion can be safely and inescapably drawn from accepted premises. Take the simple example that philosophy students inevitably encounter:

1)     Socrates is a man.

2)     All men are mortal.

3)     Therefore, Socrates is mortal.

This kind of reasoning promised to escape the flaws of human bias, frailty, and confusion, lending authority to all that he wrote. If he can be trusted with logic, why not trust what he says about the universe?

Building on the logical works are Aristotle's theories of physics and what came to be called metaphysics-literally, "what comes after physics." Aristotelian cosmology eventually ascends to a divine being he claimed to know neither by faith nor tradition but exclusively by thinking.

Like Plato's Laws, Aristotle begins with a meditation on movement in the world. One thing moves another. Moving things form a chain reaction of causes and effects and effects becoming causes, a churning and eternal cycle. There was no beginning; motion cannot have come from nonmotion, he reasons, so the universe must always have existed, always in motion. But every motion has to be caused by something. This is important. Wisdom, says Aristotle, is knowledge of causes.

The sequence of things causing other things cannot be infinitely long, however, even if it goes on eternally; you can turn a chain necklace round and round your neck but only because it has a finite number of links. Aristotle held that an infinite number of anything is impossible, for any number of things will still be less than infinity. Besides, if you start counting infinitely many causes away, you'll never reach the effect. So if there's a finite number of causes, one of them has to be first, and it holds all the others in place. To stay on your neck, a necklace needs to have a clasp.

The journey upward, through the sequence of causes he finds in the world, brings Aristotle past the stars and planets. He takes them to be the eternal gods hinted at in the myths of tradition, going about their orbits in perfect order, forever. When he reaches what moves them, the journey comes to its destination: that which is also eternal but eternally unmoved by anything else. He wonders, in a tangent, whether there could be many such beings (47 or 49, or maybe 55) but concludes not, repeating a line from the Iliad: "Too many kings are bad-let there be one!"

This unmoved mover isn't simply the finger pushing over the first in a line of dominoes at the beginning of time. This mover-call it God-is the whole purpose of the whole game, through all eternity. It's the final cause of everything, though never by physically, materially acting on the world. As every domino falls, this is the overriding reason, the gravity. While "all other things move by being moved," Aristotle explains, the first and final cause isn't moved by anything else, even while it moves everything. It "produces motion as being loved." His God is pure thought, pure purpose, and the sum of all that the universe aspires to.

This is a God mired in the daunting system of the theories, definitions, and assumptions of Aristotle's entire corpus, veiled from the uninitiated like the secrets of a mystery religion. And for what? There can be no friendship between people and God, and there is no need to bother with prayer or worship. Though Aristotle describes God as a soul something like human souls, it doesn't condescend to commune with us. Though it acts as the benevolent governor of the natural order, it offers no hope of special miracles.

What, then, does God do? The most perfect thing one could do, says Aristotle: God thinks. But God can't think about just anything. This perfect God can only think about what is perfect. "Therefore," he concludes, "it must be of itself that the divine thought thinks, since it is the most excellent of things, and its thinking is a thinking on thinking." With this formulation comes the ultimate apotheosis of the philosophers' logos culture, a mind without a body, a self-thinking thought. At least so far as we mortals can know, this God is proof and nothing else. 

The Gospel of John, written toward the end of the first century, starts out this way: "In the beginning was the logos, and the logos was with God, and the logos was God." It is a passage, with logos translated as "Word," that I first discovered in high school, in the pages of an old King James Bible my mother had been given by her father in his late-life pious phase-compact and quaintly illustrated, between beige leather covers that could zipper closed. These peculiar phrases caught me with their poetry and what I could make of their meaning. Recalling the first words of Genesis, the act of creation, the language of John's Gospel implies that the whole fabric of the universe is reason, language, and logic-what the Greek philosophers were talking about. I kept reading more and more from the Bible and its exotic promises. A few verses later: "Behold the Lamb of God, which taketh away the sin of the world!"

A problem with trying to record this "history of my religious opinions"-in John Henry Newman's phrase, betraying the narcissism of my task-is that they disappear. I began keeping a journal only a few days after my sixteenth birthday, which is the beginning of a record that can confirm or deny what fragments I actually remember. It started as an assignment in my first writing class. At night, before bed, I would sit with that spiral-bound blue notebook and do battle against the pages, scribbling one claim and denying it a sentence later, or twisting what was at first dead serious into a bad joke. I had something to say that only writing could draw out-something important, it felt like-but I didn't know what yet. Day after day I tried.

God was a question I kept clear of at first. When forced to consider religion by something I had read or seen, the sentences became even more contorted than usual. Once, I went to a concert at a local Baptist church with a friend and wrote, I felt like we had just entered hostile territory. But the place reminded me, if only by contrast, of a thick book I had just read and barely understood, The Brothers Karamazov. I remembered some things the monk Zosima said about his love for his God. Maybe they should read this shit, I cussed. Believe in it or not, it is as true as anything could ever be. What in the book is true exactly, or how, I don't say.

One of the very earliest entries I find in my journals opens bluntly: Today, my parents told me they are separating. They had brought me to my father's office in the basement of our house to say so. I sat in the squeaky leather chair and listened as my father, mainly, talked from the far corner of the room and my mother, beside me, mainly stayed silent. That night my world bifurcated.

This was on top of the already shaky foundations of an uncomfortable body, an erratic mind, and the malaise of suburban life. I wrote about having this feeling of "skin hurting"-when I feel like there's absolutely nothing I can do to make my life bearable again. It came and went, without warning or good reason, except adolescence. It's a story familiar to many of us in this generation, we "millennials": two houses, lonely neighborhoods, and the feeling of being at the mercy of forces beyond our understanding. From initial conditions like these, spelled out in the details of each particular case, each of us has our own story. Really-divorce or not, millennial or not-nobody evades this basic problem: out of the multitude of stage sets, other people, and stray ideas, a person must be made and a mind must be made up.

I could recognize myself in that word from John's Gospel, sin; it was my private shame about one thing or another, and the universal but surprisingly difficult process of discovering that I was a mess. Through all this, I wrote and wrote in my journal. I've been playing with ideas of sin, I recorded one day. I never liked to say anything too specific, for fear of who might someday read it, but you can imagine. Religious words started becoming a code to myself. In confession, in absolution, and in starting anew I am recognizing with every moment my sins and my failures and my own cruelty to myself in expectation and of the world-and so on. These pages are tough going. Why do I burn so unsatisfied? I beg. I cannot imagine what satisfaction I require, what could possibly soothe my desires, what could bring me some peace.

I wasn't sure I believed in God, exactly, but I could say "God" this and "God" that, writing to the word, with it, and through it. God, as logos, was a word before becoming a being or a belief. It was infinite love, the opposite of that irrepressible sin. Somehow the theological idiom started to work. It gave me a license to forgive myself that I didn't have otherwise, and to keep trying to be better. Scattered pieces of thoughts coalesced into sense, and into sentences, making the entries gradually more readable to my eye today. It was as if John's promise were coming true; there really was hope against sin to be found in a certain divine Word and, through it, a means of expression.

In early Christianity, Greek philosophy found both a challenger and a new lease on life. This new religion had one God (kind of like Aristotle's unmoved mover) who created the world (kind of like Plato's dēmiourgos) and promises eternal life (as, much of the time, did Plato). It became a popular speculation that the pagan philosophers, aided by the divine logos, must somehow have perceived the truth that Christ would reveal. But philosophy alone was not sufficient.

"Jews demand signs and Greeks desire wisdom," the apostle Paul wrote to his followers in the Greek city of Corinth, "but we proclaim Christ crucified." So there, he's saying, love unto death. The image is shocking. It's hard to do ordinary philosophy with a bloodied and tortured and executed God, one who forgave his executioners, who commands us to love our enemies. This is seemingly unthinkable. Yet, for Paul, "We have the mind of Christ." Mind, logos-he's preaching philosophy, crucified. Its first axiom is that act of self-sacrifice, made out of love.

The new Christian synthesis found decisive expression in Augustine of Hippo, a fourth- and fifth-century North African bishop. He would become the most influential theologian of Latin Christendom. Augustine ended up placing grace-given faith on a pedestal above reason, but he didn't do so for lack of thinking. In his Confessions, we meet a man who searches for truth through intellectual mazes, reading this, hearing that, and discussing this. Before becoming a Christian, Augustine had been a follower of Manicheanism, whose adherents professed to believe about God only what could be known through reason. But after meeting the famous Manichean leader Faustus, Augustine decided this claim was a fraud. "Nothing," he wrote, "would remain stable in human society if we determined to believe only what can be held with absolute certainty." Life cannot be lived by proof alone.

The Confessions itself attests to this. It takes ideas seriously but refuses to wrest them from personal history. It begins with his childhood and ends with a commentary on Genesis. Memories mix with a treatise about memory. He comes to his God by seeing what is so fragile and disordered in himself. Sound familiar? I can't help but imitate it.

In one essay, "Concerning Faith of Things Not Seen," Augustine compares believing in an unseen God to trusting a friend. We trust our friends because we want to and have to, before we really know they're as good as their word. If we didn't, they would have no chance to prove themselves. "And thus," he writes, "when you commit yourself in order to prove, you believe before you prove." He wanted to tame the longing for proof, to temper it.

This doesn't mean, though, that there's nothing to go on at all. In The Free Choice of the Will, he offers something more like an actual, and actually quite detailed, argument for God's existence. It's written as a dialogue. Like Plato's cave, it takes the light of the sun as a metaphor for the one truth-and good and beauty-that illuminates the world. This truth must be a reality higher than any human mind, everlasting and unchanging. He reflects on numbers, on how arithmetic is the same for everybody. And on wisdom, which chooses what is more perfect over what is less. Plato would be nodding at every step. Augustine goes on to talk about the pleasure of discovering the truth that is highest and most perfect, and how truth is our guide to happiness. This universal truth, he says, is God.

He seems to like the proof, and even rejoices at the end of it-but only for a moment. Ultimately, he doesn't want a religion made of proofs. There's no Christ in there, for one thing; one must hold to Christ by faith, Augustine instructs. Human reason has limits, and it depends above all on divine revelation and grace. Christians before and after him therefore had to worry that proofs might be a sin against humility, against the proper posture of human beings before their crucified God.

The major character in the Confessions, besides Augustine himself, is his mother, Monica. She was a Christian and hoped that her wayward son would become one too. He finally did convert while far away in Italy, where his thoughts caught up with her influence; Monica was made a saint for the role she played in his conversion. But she didn't lead him by proofs-instead, by her faith, her love, and those powers and pressures that only a mother can exert. It turns out that my own mother's birthday, August 27, is Monica's feast day.

I was still little when Mom discovered Ramana Maharshi-not to be confused with the Beatles' Maharishi-a man who had spent his life on a mountain in southern India, as little concerned with metaphysical proofs as with material possessions. Maharshi sat in silence, composed hymns to his mountain, Arunachala, and answered the questions people asked him. Though he had died fifty years earlier, my mother was growing more and more devoted to him and his teachings. I witnessed her turn to meditation, to walks in the woods, and to learning Sanskrit, determined to find the peace that she believed must lie beneath the pain of divorce. A hundred different ways, she would tell me that no search is more worthwhile than the search for the highest.

Meanwhile, what my father turned to was more of this world. He remarried, designed gardens for his clients, took up poker, and adopted a cat. He started going on trips back to Italy, and switched from making family trees of the English royals to even more magnificent, full-color ones of the Medicis. Dad's rescue was in the people and places around him, while the help my mother sought took her further inward. I wanted some of both.   

As they fell apart, my center didn't hold. I would have to find one of my own. I kept on reading Mom's Bible and, when she wasn't home, borrowing her books about meditation. I remembered the few prayers that she insisted I memorize as a child-the Lord's Prayer and the Twenty-Third Psalm. I visited local churches on Sundays and during the week ducked into their prayer chapels, trying not to be seen, since I didn't know what to do in front of an altar or in a pew. The very foreignness of those places, though, was a new home. My parents had always told me that what I believe would be up to me, and now it really was. Urgently.

Plato thought that all learning is really recollection, remembering what one's soul already knew from the eternal forms before birth. Religion felt to me like a rediscovery. Even as I tried to hide what I was up to, my mother kept encouraging me. She has given me the essentials. She has given me the search, I wrote, after I had come to accept my new obsession. But my mind, that is truly my father's. I brought to the search his skepticism, his feeling, and the desire, at least, for his meticulousness. By the middle of my senior year in high school, I could hardly think about anything else.

Augustine stressed that his capacity for faith came from God. But the desire for it, the pining, and the asking-that was from his mother, Monica. These drove him into doubts so deep that the only way out would be a new kind of conviction. "I have become a question to myself," he writes in the Confessions. God became a question for me.   

During Augustine's life, the Roman Empire was collapsing, and its fall would consign the genre of proof to obscurity in the West for centuries. The end of ancient philosophy is usually marked by the murder of the philosopher Hypatia, daughter of the librarian of Alexandria, at the hands of a Christian mob in the year 415. Greek thought nearly disappeared from Europe, and away with the philosophical classics went the God of reason. Other religious genres took over instead among Christians: the suffering of martyrs, mystical prayer, cathedral building, asceticism, crusades. But wherever the Greeks were still being read, the genre of proof would live on in other guises.