Did It All Start with the Big Bang? And What Difference Does That Make for the Meaning and Purpose of Our Lives?

I have written about "The Big Bang Theory"--the popular television show that ran on CBS from 2007 to 2019.  Every episode began with a clever theme song that ended with the line: "It all started with the Big Bang."

Is that true?  The brief answer is: We don't know.  

We don't know because the earliest history of the universe is beyond what we can observe.  Whatever is beyond any possible observation cannot be known to exist or not to exist.  Asserting its existence is a matter of belief or faith, not a matter of scientific knowledge.  It's an assertion of religion (or revelation) not of science (or reason).  Here I agree with physicist Sabine Hossenfelder's insistence that scientific models of reality must always be tested against observational evidence because otherwise they are just speculative stories that are more like religion than science (Hossenfelder 2022).

What difference (if any) does this make for how we think about the purpose of our lives?  The brief answer is that we must choose between at least two alternatives.  We can believe in a divinely caused Big Bang that can support a moral cosmology that gives our lives a divinely appointed purpose that might include eternal life after death.  Or we can recognize a moral anthropology that gives our lives a human purpose in satisfying our natural desires--such as the desire to understand the universe, which can be expressed either as a desire for religious understanding through Revelation or a desire for intellectual understanding through Reason.

If human beings are to be free to pursue these alternative ways of life and to debate their relative merits, people must have the religious and intellectual liberty secured in a Lockean liberal open society that allows for freedom of thought and expression.  The kind of freedom that is manifest even in some popular culture such as the "Big Bang Theory" television show.

THE BIG BANG?

Human beings wonder about their origins.  They want to know where they came from.  They ask about not only their ancestral and social origins but even about the origin of everything.  That's why every human society has stories about how all things came to be as they are.  Commonly, they are religious stories about how divine beings brought the world into existence.  "In the beginning God created the heaven and the earth."  So declares the first verse of the King James Bible.

But what exactly does that mean?  And is it true?  Some theologians have said that God created everything ex nihilo (from nothing).  But others have said He created everything ex materia (from some preexisting material).  Some have said God created only one universe--the one that we live in.  But others have said that He might have created other universes, perhaps even an infinite number of them.

Some philosophers and scientists (like Aristotle) have said that there was no need for divine creators because the world was eternal as composed of eternal matter and thus had no beginning and no end.  But others (like Lucretius) have argued that the world has arisen spontaneously from the random motion of atoms without any need for divine intervention, and that atomic flux would eventually dissolve every world and create a new one.

Thomas Aquinas defended the orthodox Christian doctrine that God did indeed create everything from nothing.  But he admitted that this could not be scientifically demonstrated.  "It is by faith alone do we hold and not by any demonstration that can be proved, that the world did not always exist. . . that the world began to exist is an object of faith, but not of demonstration or science" (ST, I, q. 46, a. 2).

But then when Georges Lemaitre (a cosmologist who was also a Jesuit priest) first proposed a Big Bang theory of the universe, Pope Pius XIII pointed to this as a scientific demonstration of the divine creation of the universe from nothing.  Lemaitre himself, however, criticized the Pope for failing to see how this scientific theory had nothing to do with the Christian doctrine of creation, which could be believed by faith but not known by demonstration.

As I have indicated in my essays on the Big Bang, the scientific theory of the Big Bang has been invoked by some people (like William Lane Craig) to prove that God exists and by other people (like Stephen Hawking) to prove that God does not exist.  I have argued that both are mistaken.  

Craig states his argument as a syllogism:

 1. If the universe began to exist, then there is a transcendent cause which brought the universe into existence.

2. The universe began to exist.

3. Therefore, there is a transcendent cause which brought the universe into existence.

There are good reasons to doubt that those two premises are really scientific statements rather than affirmations of religious faith.

The first premise is not "obviously true," as Craig says, because while we all have experience of how natural causes work within the universe to bring things into existence, we do not have experience with how transcendent causes work outside the universe to bring the universe itself into existence. 

Consequently, while the "principle of sufficient reason"--that for everything there must be a causal explanation--might hold true for our ordinary experience of how things work within the universe, this principle does not necessarily apply to what things are like outside the universe, because none of us has ever stood "outside the universe" to see if the principle of sufficient reason holds true there.  Standing "outside the universe"--experiencing the transcendent or the supernatural--is a matter of religious imagination that is beyond our empirical experience of the world and thus beyond empirical science.

Therefore, the first premise of Craig's syllogism might be a statement of religious faith, but it is not a statement of scientific truth.

The same can be said about the second premise.  "The universe began to exist."  What exactly is being stated here?  There are two possibilities.  The universe began to exist out of nothing.  Or the universe began to exist out of something. 

Craig's argument requires that he equivocate between these two different statements.  The universe began to exist out of nothing is the Christian theological doctrine of creation ex nihilo.  But, then, this would deny Craig's claim that this premise is "religiously neutral."  In fact, that the universe began to exist out of nothing is not a scientific statement at all, because there is no human observational experience of absolute "nothing" that would make the study of "nothing" part of empirical science.  I even doubt that any of us really understands what we're saying when we talk about absolute "nothing," because it's beyond ordinary human experience.

And yet scientists like Stephen Hawking do speak about how the Big Bang could have come from "nothing" without any need for God.  His explanation is that "the laws of nature we call quantum mechanics" tell us "that not only could the universe have popped into existence without any assistance, like a proton, and have required nothing in terms of energy, but also that it is possible that nothing caused the Big Bang.  Nothing" (Hawking 2018, 34-35).  Far from the Big Bang proving God's existence, as Craig claimed, Hawking claimed to have shown that since nothing caused the Big Bang, God does not exist.

Hawking appeared five times on the "Big Bang Theory" show as the one scientist that Sheldon most admired.  He playfully mocked Sheldon, but he also recognized his brilliance.  Nothing was said about Hawking's atheism.

Notice that in his argument for atheism, Hawking had to assume at the origin of the universe the reality of the laws of quantum mechanics and of quantum vacuum states.  That's not nothing!  That's something!  Notice also that Hawking had no explanation for where those laws of physics came from.

Moreover, Hawking's model for the origin of the Big Bang is only one of many Big Bang models that scientists have proposed over the past 30 years.  By some counts, there are over two dozen such models (Afshordi and Halper 2025).  Some physicists say our universe is one of infinitely many universes, and each one is a bubble in a rapidly expanding quantum fuzz.  Others say the Big Bang started from the hot gas of tiny, vibrating strings.  Others say the Big Bang was a bounce of a collapsing universe into an expanding one.  Others say the universe is always in a state of eternal inflation.  In this video, Phil Harper gives the top ten answers to the question of what happened before the Big Bang:

Remarkably, in the end, it doesn't matter which model you choose because you end up with the same outcome--the universe that we live in today.  That it doesn't matter which story you believe points to a fundamental problem: there is no data to tell us which model is right.  The reason for that is that the fundamental constituents of nature are either too small, too far away, or too far in the past to be observed directly by us or indirectly through our instruments, and thus nature's secrets are buried so deep or so far away that we have no way to test our theoretical speculations about them.

Below is a sketch of the limits on the scale of human observational experience of nature.  At the small scale, microscopes have extended our experience beyond our visual reach, and the Large Hadron Collider (LHC) has extended our reach even deeper.  We have gone from scales of centimeters to millionths of a millionth of a millionth of a centimeter.  But we have reasons to believe that the fundamental constituents of nature that string theory attempts to describe lie at a distance scale 10 million billion times smaller than the resolving power of the LHC.  At the cosmic scale, telescopes have extended our experience of the astronomical universe; but no telescope will ever look beyond our universe's cosmic horizon and see the other universes assumed by the multiverse hypothesis.  The white area is the range of scales within human experience.  The grey area is outside that range.  You can click on the image to enlarge it.

Notice that the limit of the observable universe at the right end of this scale is the cosmic microwave background.

The oldest light we can see is the cosmic microwave background, emitted nearly four hundred thousand years after the hot Big Bang some 13.8 billion years ago.  It is almost perfectly uniform, with tiny variations in temperature at 1 part in 100,000, which are shown as red (hot) and blue (cold) spots.  This is the most important store of data for early-universe cosmology.  Multiple satellites with telescopes have studied these fluctuations.  Shown here is the most recent map produced by the European Space Agency's Planck satellite probe.

This illustrates how we can make and use technical instruments (such as telescopes) to extend the range of our observational experience of nature.  But it also illustrates the limits on how far that extension can go. 

When Aristotle explained his theological cosmology of a geocentric universe in De Caelo ("On the Heavens"), he admitted that it was hard to study the heavenly bodies--the stars, the sun, the planets, and the Moon--because "we have very little to go on, and we are placed at a great distance from the phenomena that we are trying to investigate," and "very few of their attributes are perceptible by sense experience" (286a7, 292a15-b25).  

So when Galileo defended his Copernican heliocentric system, he argued that Aristotle would have been persuaded by the evidence that Galileo had gathered from his telescope because Aristotle would have welcomed the use of the telescope to extend the range of human observational experience of distant planets and stars.

In the 400 years since Galileo, telescopes have become more powerful; and sending telescopes into space has expanded the depth of their observational power.  So that now we have stunning images of deep space from the James Webb Telescope and images of the cosmic microwave background that take us back over 13 billion years into the history of the universe.  But notice that the image of the cosmic microwave background is dated at four hundred thousand years after the Big Bang.  It's not clear that we will ever get any closer than that to the Big Bang, or to whatever there might have been before the Big Bang, which might forever be beyond our range of observational experience.  

Consequently, it will be impossible to test our models of the Big Bang against observational data, which will mean that our models will be little more than speculative origin myths that rest on belief or faith rather than scientific knowledge.

COSMIC PURPOSE?  HUMAN PURPOSE?

Asking about the origins of the Cosmos might seem like a very abstract kind of questioning that doesn't have much to do with ordinary human life.  But in fact it's one of the fundamental questions that we must ask as we try to make sense of our lives.

Must we believe that in the beginning God created the Universe and created man in His image if we want to give some cosmic meaning to our lives?  If this Divine Creator cares about us and for us, and if He endowed us with a knowledge of His moral law as an eternal standard of right and wrong to guide our moral life, and if He promises to help us live according to that moral law, or to save us from our sinful flaws, and then to reward those who love Him with eternal life, doesn't that give us a cosmic purpose to our lives?

But if we believe that in the beginning the universe arose through some impersonal process of natural evolution of matter and energy, and if eventually we somehow emerged as but blips of complexity in that uncaring universe, then how can we believe that our life has any meaning if there's no purpose to it?

Or should we see that even if there is no cosmic purposefulness in our lives grounded in the moral cosmology of a divinely created universe, there is a natural purposefulness in our lives grounded in the moral anthropology of our natural human desires?  Even if we live in an uncaring universe, we care for ourselves, and we strive to satisfy our natural desires.  Perhaps that is what makes our lives meaningful.

And so, for example, all human beings have some natural desire to understand the universe and their place in it.  This began when natural selection favored species that made correct predictions about their environment, and then organisms became increasingly better at understanding nature, until the evolution of the human cerebral cortex reached a point where human beings could understand their world by probing deeply into nature through intelligence, symbolism, and observation.

But then this natural human desire for understanding could be expressed either as a desire for religious understanding or a desire for intellectual understanding.  Human beings moved by the desire for religious understanding could imagine that they and their universe were created by a supernatural Mind analogous to the human mind.  Human beings moved by the desire for intellectual understanding could imagine that they and their universe were created by natural laws of evolution.  Some human beings can be theistic evolutionists who believe that God originally created the laws of nature and then allowed the universe to evolve naturally according to those laws, while occasionally intervening miraculously in that natural history to reveal Himself to human beings.

The tension between the natural desire for religious understanding and the natural desire for intellectual understanding is manifest in the Reason/Revelation Debate.

THE REASON/REVELATION DEBATE IN "THE YOUNG SHELDON"

Much of "The Big Bang Theory" revolves around Sheldon and his life story.  He grew up in East Texas in a Southern Baptist family that struggled to understand him because he was a child prodigy with an IQ of 187, who used his intelligence to make scientific arguments against religious belief.

From 2017 to 2024, CBS broadcasted a spin-off prequel--"Young Sheldon"--about Sheldon's childhood in the 1980s and 1990s.  The theme of scientific cosmology as supporting atheism against religious belief continued in this show.  

Pastor Jeff is the minister of the Southern Baptist church where the Cooper family goes every Sunday.  The young Sheldon is determined to show everyone that he can use science to refute Pastor Jeff's religious beliefs by arguing that the Bible's story of Creation is denied by the evidence for the natural evolution of the universe and human life.

One example of this conflict between science and religion is the third episode of the second season (airing on October 4, 2018) entitled "A Crisis of Faith and Octopus Aliens."  This episode begins with the Cooper family attending church on a Sunday.  Pastor Jeff is delivering his sermon, and suddenly Sheldon raises his hand to ask a question.  He challenges Pastor Jeff to tell him what God would look like in an alien planet inhabited by octopuses.  Would God look like an octopus?  Jeff struggles to answer.

Then, that Sunday afternoon, Sheldon's mother Mary receives a phone call and is told that the 17-year-old daughter of her friend Stephanie Hanson had died in an accident.  Mary and her husband George go to the funeral.  Throughout the week, Mary is troubled by the question of why an all-good God would torture a good Christian like Stephanie by killing her innocent child.  She talks with Pastor Jeff, but he cannot give her a satisfactory answer.

On Saturday night, Mary takes her mother to a bar named "Lucky's Place," where they drink and play billiards.  She tells her mother about her religious struggle and how this has depressed her mood.  She is drunk, and she is driven home by her mother.  Her husband George takes her to bed.

The next day, Sunday, she does not go to church, and she does not say a prayer at the family dinner.  Her husband and children are shocked to see these signs that she is doubting her faith in God.

Later, in the evening, Sheldon comes out to the front porch of their house to talk with her and attempt to comfort her.  Here's the scene:

Notice that even though Sheldon is an atheist, he makes a scientific argument for the existence of God based on the "fine-tuning" of the universe.  The strength of gravity must be mathematically precise--neither too strong nor too weak--to make it possible for the universe to exist as a place where human life can emerge.  Isn't it unlikely that that could be just an accident?  Doesn't this logically suggest the need for God to design the precise conditions that make the universe and life possible?  Sheldon indicates that he is still an atheist, but he does see this as a scientifically logical argument for religious belief.

Mary responds by saying that her problem with God is not a matter of logic in her head but what she feels in her heart.  Sheldon then makes another argument that might appeal to her heart.  In a world of over five billion people, how likely is it that I would have the one woman who is a perfect mom for me?  Mary is moved by this, and she thanks God for giving her Sheldon as her child.  In the voice-over, the adult Sheldon tells the viewers that he didn't tell his mom that he shouldn't have to share credit with God for making the argument that comforted her.

One of the YouTube clips of this scene has a comment from "B Sharp" about Sheldon's first argument:  "I love Young Sheldon, and this is a sweet moment.  However, Sheldon is using the fine-tuning apologetics argument, which is fallacious.  The universe wasn't created for humans.  Humans evolved to exist in this universe."

One could also respond in a similar way to Sheldon's second argument.  That a son loves his mother is not an unlikely event that requires some supernatural intervention, because parent-child bonding is an evolutionary adaptation of human nature.

But then what if evolved human nature includes a natural desire for religious understanding--for transcendence and transcendent meaning?  This emotional desire is not based on pure logic, and therefore it cannot be refuted by logical argument.  And, therefore, as Rebecca Goldstein has shown, the emotional longing for religious transcendence prevails over scientific reasoning, particularly when science faces fundamental mysteries in the universe that cannot ever be explained by reason alone; and thus Revelation cannot be refuted by Reason.  Perhaps this is what Mary Cooper meant when she pointed to what she felt in her heart.

Nevertheless, the fine-tuning argument is one of the best scientific arguments for God as the Intelligent Designer of the universe.  Christian astrophysicists like Owen Gingerich and Deborah Haarsma like to invoke this argument.  And yet, I have written some posts indicating the flaws in this line of reasoning.

It is not really clear, for example, that scientific cosmology shows that the universe is precisely fine-tuned for life, and particularly human life.  Most cosmologists agree that the universe will come to an end, and that all life will be extinguished.  Consider one line in the theme song for "The Big Bang Theory":

"It's expanding ever outward, but one day it will pause and start to go the other way, collapsing ever inward, we won't be here, it won't be heard.  Our best and brightest future that it'll make an even bigger bang!"

Does the end of the universe in a Big Collapse mean that far from being fine-tuned for life, the universe has been fine-tuned for death?  Or should we have faith in those eschatological religions that promise us eternal life after death?

In a liberal open society, we are free to openly debate such questions--even in popular television shows--without fear of persecution.

And in that debate, one of the big questions for us will be:  Did it all start with a Big Bang?

REFERENCES

Afshordi, Niayesh, and Phil Halper. 2025. Battle of the Big Bang: The New Tales of Our Cosmic Origins. Chicago: University of Chicago Press.

Hossenfelder, Sabine. 2022. Existential Physics: A Scientist's Guide to Life's Biggest Questions. New York: Viking.

Does the Search for Extraterrestrial Life Deny Christianity?

 

                              Jupiter's Four Galilean Moons--Io, Europa, Ganymede, and Callisto

                 The European Space Agency Launches the Jupiter Icy Moons Explorer (JUICE)

JUICE's Journey to Jupiter with Gravity Assist Flybys at the Sun, the Earth, and Venus

On April 14th, the European Space Agency (ESA) launched the "Jupiter Icy Moons Explorer" (JUICE) spacecraft on its way to Jupiter to explore three of the major moons of Jupiter--Europa, Ganymede, and Callisto--including a prolonged orbit around Ganymede, the largest moon in the solar system.  Because Jupiter is so far away from the Earth, and because of the need for gravity assist flybys of the Sun, Earth, and Venus, the spacecraft will not reach Jupiter until July of 2031.  In the fall of 2024, NASA will launch the Europa Clipper to explore Jupiter's Europa.  Clipper will launch on a SpaceX Falcon Heavy rocket, which is a more powerful launch vehicle than ESA's, and consequently Clipper will actually reach Jupiter in April 2030, a year ahead of JUICE.  

One of the primary reasons for these exploratory missions to the moons of Jupiter--and particularly, Europa and Ganymede--is to look for signs of extraterrestrial life.  We might wonder why human beings want to search for extraterrestrial life.  Is this a foolish pursuit?  What difference would it make for us if life were discovered on these moons?  

Can Christians accept this?  Or must Christians insist that we know from the Bible that the only form of extraterrestrial life is angels (supernatural spirits without bodies), and so extraterrestrial embodied life is impossible?  Or could the discovery of extraterrestrial material life beyond the Earth be understood as compatible with the central doctrines of Christianity?

The four largest moons of Jupiter were first discovered in January of 1610 by Galileo when he turned his newly invented telescope towards the night sky.  In March of that year, he published his discoveries in The Starry Messenger.  For many reasons, this was one of the most important discoveries in the history of science.  One reason was that it seemed to be clear evidence against the geocentric model of the universe and for the heliocentric Copernican model, because Jupiter's moons were orbiting around Jupiter and not around the Earth.  Another reason for the importance of this discovery is that some people saw it as suggesting the possibility of extraterrestrial life.  Johannes Kepler published a letter to Galileo, which included his claim that Galileo's discovery of the four moons made it probable that there was life on Jupiter.  After all, if Jupiter with four moons is so similar to the Earth with one moon, then why shouldn't Jupiter have living inhabitants just as the Earth does?  Galileo himself, however, cautiously resisted Kepler's suggestion.  

But despite Galileo's caution on this point, the telescopic discoveries in astronomy, beginning in the 17th century, renewed a debate over the possibility of extraterrestrial life that had begun in ancient Greece and then reappeared in the late 13th century as a debate among Christians over whether extraterrestrial life was compatible with Christianity.  The documents in this debate have been conveniently collected in one volume by Michael J. Crowe in The Extraterrestrial Life Debate, Antiquity to 1915: A Source Book (University of Notre Dame Press, 2008).  

An assessment of this debate from the perspective of a conservative Catholic has been written by Benjamin Wiker--"Alien Ideas: Christianity and the Search for Extraterrestrial Life" (Crisis Magazine, November 4, 2002).  Wiker argues that the search for extraterrestrial life is an anti-Christian attack on religion rooted in the atomistic materialism of Epicureans like Lucretius.  I have already challenged Wiker's stance in a series of posts.

Against Wiker are those Jesuit astronomers who work for the Vatican Observatory, who see no conflict between the possibility of extraterrestrial life and Christianity.  Some years ago, Jack Hitt wrote a long article on how these Catholic scientists think about this debate--"Would You Baptize an Extraterrestrial?" (The New York Times Magazine, May 29, 1994).

In his didactic philosophical poem--On the Nature of Things--Lucretius defends the Epicurean understanding of nature as arising from the spontaneous, random, and purposeless motions of atoms, without any need for intelligent design by the gods.  From this atomistic conception of nature, he infers that "it is in the highest degree unlikely that this earth and sky is the only one to have been created and that all those particles of matter outside are accomplishing nothing," and that we are bound "to acknowledge that in other regions there are other earths and various tribes of men and breeds of beasts" (2.1056, 2.1078).  He thus affirmed the plurality of worlds and extraterrestrial life.

In this way, he was opposed to Plato (particularly in the Timaeus) and Aristotle (particularly in On the Heavens and the Metaphysics), who argued that the cosmos was governed by a divine mind (Plato's Demiurge, Aristotle's Prime Mover) according to a divinely purposeful design.  They inferred from this that there was no plurality of worlds.  As Aristotle said: "the unmovable first mover is one both in definition and in number; so too, therefore, is that which is moved always and continuously; therefore, there is one heaven alone" (Metaphysics 1074a37-39).  (I have written some posts contesting these popular interpretations of Plato and Aristotle as proponents of cosmic divine teleology as opposed to the natural immanent teleology of Darwinian natural right.)

From the beginning of Christianity, many Christian theologians have embraced Christian versions of this popular interpretation of this Platonic and Aristotelian theological cosmology as opposed to Epicurean atomism, and this has led them to deny a plurality of worlds with extraterrestrial embodied life.  But beginning in the late 13th century, some Christians have seen a plurality of life-worlds in one cosmos as compatible with Christianity.

The debate here is over whether the plurality of worlds can be reconciled with the central doctrines of Christianity--particularly, the Story of Creation and the Story of Salvation.

THE STORY OF CREATION

The key Biblical text for the Story of Creation is the opening chapters of Genesis with its account of the six days of creation.  

"In the beginning, God created the heavens and the earth" (Genesis 1:1). On the first day, God created light and separated it from darkness.  

On the second day, God created the vault that He called "sky" to separate the water above the vault from the water below the vault. 

On the third day, God gathered the water under the sky to one place, so that the dry ground appeared.  He called the dry ground "land," and the gathered waters "seas."  He then allowed the land to produce vegetation--seed-bearing plants and trees.

On the fourth day, God let there be two great lights in the sky to separate day from night on the Earth.  The greater light (the Sun) would govern the day.  The lesser light (the Moon) would govern the night.  He also made the stars in the vault of the sky to give light on the Earth.

On the fifth day, God allowed the seas to teem with marine animals, and he allowed birds to fly above the Earth across the vault of the sky.

On the sixth day, God allowed the Earth to produce the land animals.  And then, God said, "Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the Earth, and over every creeping thing that creepeth upon the Earth" (Genesis 1:26).

The first problem for any reader of this first chapter of Genesis is deciding how much of this was intended to be interpreted as literal history and how much of it is figurative poetry.  Deciding that question is crucial for determining whether this Biblical account of Creation can be compatible with the natural sciences of cosmology, astronomy, geology, and evolutionary biology.  As I have indicated in previous posts, Christians cannot reach any agreement on this issue, which is most evident in how revelation through the Holy Spirit has failed to resolve the creation/evolution debate among Christians.

Consider what a literal reading of this first chapter would teach us.  God created everything in the Universe in six days.  The Universe is geocentric in that the Earth is at the center.  (Wiker observes that "early Christians held to a geocentric universe.")  Above the Earth, the sky is a solid vault that separates the waters above from the waters below, which is the boundary between heaven and earth.  This cosmic geography saw the sky as having a form and function similar to what was found in the ancient Near East.  Most people believed that the sky was solid.

In that solid sky, there were the Sun, the Moon, and the stars.  The Earth was the only planet in the Universe.  And the Moon was the only moon in the Universe.  The stars did not have any planets orbiting around them.

All life was found on or a little above the Earth.  So, there was no extraterrestrial life.  There were, however, divinities or spiritual beings (angels?) who lived in the heavens.  Notice that when God speaks of creating human beings, He speaks in the plural ("Let us make man in our image").  The Bible often has God speaking in the plural (for example, Gen. 3:22; 11:7; Deut. 32:8; Job 1:6; 2:1; Isa. 6:8.  Sometimes, God sits on a throne and meets in a council with "all the multitudes of heaven standing around Him" (1 Kings 22:19-23; Job 1:6; 2:1).  So, there was no extraterrestrial bodily life beyond the Earth.  Christians who believe this will have to say that the search for extraterrestrial life is foolish and anti-Christian.

Notice that if we accept the literal reading of the Bible's cosmology, we will have to say that modern science has shown that the Bible's teaching is false.  So, for example, if we think the Bible is teaching that the universe is geocentric, then this is denied by modern astronomy.

But then Christian scientists (like Francis Collins and Deborah Haarsma) will say that much of the Bible uses figurative stories of the sort that would have been comprehensible to the people of the ancient Near East that were not intended to be taken as literal history.  The Bible, therefore, is not a science textbook but rather a book that tells us what we need to know about salvation.  Or, as Galileo put it, the Bible tells us "not how the heavens go," but "how to get to heaven."  The scientific study of the Book of Nature must be separated from the religious study of the Book of Scripture, although the two books should ultimately be compatible.  Many scientists (like Galileo and Darwin) and many Christian theologians (like Pope John Paul II) agree on this conception of God speaking through two books.

Moreover, Christians need not read the Book of Scripture as denying the possibility of extraterrestrial life.  For example, Thomas Chalmers was one of the leaders of Scottish evangelical Christianity in the 19th century; and he wrote extensively about how the Christian Revelation could be harmonized with the enlarged cosmos of modern astronomy that might include extraterrestrial life in many worlds beyond the Earth.  In one text, he began by quoting from the book of Psalms:

"When I consider thy heavens, the work of thy fingers, the moon and the stars, which thou has ordained; What is man, that thou art mindful of him, and the son of man, that thou visitest him?" (Psalm 8:3-4)

Chalmers saw here a suggestion that God's universe is so vast and varied, extending far beyond what is visible to the naked eye, that we should see the Earth as only "one paltry and insignificant portion of it," and "how minute is the place, and how secondary is the importance of our world, amid the glories of such a surrounding magnificence."  And so, "to an eye which could spread itself over the whole, the mansion which accommodates our species might be so small as to lie wrapped in microscopical concealment; and, in reference to the only Being who possesses this universal eye, well might we say, 'What is man that thou art mindful of him, or the son of man that thou shouldest deign to visit him'" (Crowe, 245, 250, 253, 268-69).

Chalmers suggests that we can see this expansiveness of God's universe confirmed by what modern astronomy tells us about the many stars that are suns with planets orbiting around them just as our Earth orbits around its star.  And we can imagine that "worlds roll in these distant regions; and these worlds must be the mansions of life and of intelligence."  In the remote future, we can foresee that our Sun will die or the Earth will fall into it, and then our world will disappear.  But the many other worlds of life and intelligence orbiting other stars will survive.  This shows that what God did in the first chapter of Genesis to create the human world on Earth, He has done for other distant planets to create other worlds of intelligent life.  The Bible does not explicitly recognize these other worlds, but we should not assume that the Bible's silence is a denial of their existence.

THE STORY OF SALVATION

If the purpose of the Bible is to teach us "how to get to heaven"--rather than "how the heavens go"--then we must consider whether the Bible's story of salvation--based on the doctrines of Adam's Fall, the Incarnation of Christ, and the redemption of humanity through Christ's sacrifice--is compatible with extraterrestrial life.  Nicholas of Cusa in 1440 seems to have been the first thinker in Latin Christianity to affirm a plurality of inhabited worlds in space.  Remarkably, despite his radical views, the Church made him a cardinal in 1448 (Crowe, 27-34).  But then a few years later, the Franciscan philosopher and theologian William Vorilong became the first Christian author to raise the question of whether the idea of a plurality of worlds could be reconciled with the Christian doctrines of divine incarnation and redemption.  

Did the people who live on other worlds beyond the Earth sin just as Adam sinned?  If they did, would Christ have to be incarnated in each world and then die in that world to redeem them?  Or would the redemptive life of Christ on Earth be enough to universally redeem those sinners in the other worlds?  Or is it possible that the people on those other worlds did not make Adam's mistake, and so they were sinless and did not need redemption?  Chalmers implied that he could not decide between these alternatives (Crowe, 26-27, 37, 220-21, 224, 229, 242, 256-58, 325-332).

Jack Hitt reports interviewing some of the Jesuit astronomers affiliated with the Vatican Observatory and asking them about the theological implications of discovering extraterrestrial intelligent life.  Would you baptize an extraterrestrial?  One priest answered, "only if he asked for it."

The Rev. George Coyne, S.J., identified himself as a Jesuit astrophysicist.  He was a close associate of Pope John Paul II and the director of the Vatican Observatory.  Hitt reports Coyne's answer to the question: "'O.K., so I meet this 'person.'  I would ask him: 'Are you intelligent?  Self-reflexive?  In the traditional sense do you have what we can call a soul?'  Good.  'Nice to meet you.'"  He says he would then find out if their civilization sinned, then if it was redeemed, then if the redeemer was a man named Jesus, and then: 'If they say, Oh yes, now you have a theological problem.  How could Jesus Christ be our redeemer on earth and of another planet and still be the one Son of God?  Could he have had several incarnations?  That's a pretty ticklish theological problem, and I don't know the answer.'"

Wiker, however, thinks the answer is clear: "we find no evidence of speculation about extraterrestrials among the early Christians.  Not only did such speculation run directly against the central doctrinal claims of Christianity, but it also smacked of Epicureanism (which entailed, among other things, the denial of the immortal, immaterial soul, heaven, and hell).  Small wonder the early Christians tossed the Epicurean package, extraterrestrials and all, into the abyss of doctrinal errors."

Furthermore, Wiker insists, not only is extraterrestrial life a doctrinal error, there is no scientific evidence for it despite many years of scientific searching for it.  But is that correct?

ABSENCE OF EVIDENCE?  EVIDENCE OF ABSENCE?

Wiker argues:

"By the end of the 20th century, scientists had demonstrated to all but the most zealously intransigent that--humble Earth excepted--our solar system was devoid of intelligent life and most likely devoid of any life.  Further, as biologists discovered the ever-greater complexity of living organisms and the delicate balance of conditions that make them possible, it became clearer and clearer that fewer and fewer places in the universe could meet the conditions required for even the most rudimentary forms of life."

"Yet the dismal result of the high-tech search for extraterrestrials only stirred advocates all the more, resulting in the optimistic but defensive battle cry: 'The absence of evidence is not evidence of absence.'  While this might warm the dwindling fires in the enthusiast's heart, it pays little service to reason.  To be blunt, since it was the negative result of a century-long search for aliens, the absence of evidence is the evidence for absence.  What else could it be?"

But it's not quite right to speak of "the negative result of a century-long search for aliens" for three reasons.  First, it ignores the fact that the first evidence for exoplanets (planets outside the solar system) appeared only in 1996; but now, as of today, there are 5,346 confirmed exoplanets in 3,943 planetary systems with 855 having more than one planet.  There are now some estimates that there are at least 20 billion Earth-like habitable planets in the Milky Way Galaxy alone.  So, the search for extraterrestrial life on those planets has just begun within the last 25 years.

The second problem with Wiker's dismissal of the search for extraterrestrial life as a failure is that he ignores the recent intensity in the exploration of the solar system, which began in the 1970s with the first robotic exploration spacecraft, starting with the Pioneer 10 mission to Jupiter.  For example, there is plenty of evidence that the icy moons of Jupiter have liquid water oceans on them, and some of them could have geothermal and water-rock interactions on the bottom.  Europa is an ocean world entirely covered by sea ice.  Europa actually has more liquid water than does Earth!  In the 1980s, oceanographers discovered deep-sea life with a food chain based not on photosynthesis but on chemosynthesis linked to hot vents on the seafloor.  The subsurface ocean on Europa is kept liquid by heating due to tidal interaction with Jupiter. Everywhere on Earth that has these conditions gets colonized by microbial life.  Wiker says nothing about this.

That points to the third problem for Wiker.  Even though he is right that the exploration of the solar system has not found any clear evidence of extraterrestrial intelligent life, there is growing evidence for the likelihood of finding extraterrestrial microbial life (or perhaps fossil evidence of its past existence).  Increasingly, astrobiologists are concluding that microbes are the most likely forms of extraterrestrial life because the necessary conditions for such life are so much more common in the universe than the necessary conditions for intelligent life.

Wiker's insistence that we are unlikely to ever find any evidence for "even the most rudimentary forms of life" beyond the Earth is implausible, because he is silent about the growing evidence for likely conditions favorable to microbial life in places like the oceans of Europa.  Does Wiker believe that if we were to find microbes on one of the icy moons of Jupiter, that would deny the central doctrines of Christianity?

Finding microbes in the Solar System beyond the Earth or on exoplanets might not seem spectacular.  But consider the implications.  This would show that the processes that lead to the origin of life are not peculiar to the Earth, and they might be common in the Universe.  The history of life on Earth has been one of continual development from the simplest forms of life to the most complex, with every increasing degrees of living sensitivity and intelligence.  If life is a general phenomenon in the cosmos, then so is intelligence.

And with the evolutionary development of symbolic intelligence, there will be minds capable of asking questions about the intellectual and spiritual meaning of it all, and about whether their extraterrestrial souls need to be saved.

Was Man Created in God's Image? Or in the Image of Primates, With 16 Billion Neurons in His Cerebral Cortex?

 

                                  The Hidden Neuroscience in Michelangelo's "Creation of Adam"

THE CREATION OF ADAM'S PREFRONTAL CORTEX

Michelangelo's "Creation of Adam" is his visual depiction of the teaching in Genesis 1:27--"So God created man in his own image, in the image of God created he him; male and female created he them" (KJV).  Remarkably, Adam's body is already fully formed, but God is going to transmit to him something essential to his humanity through God's extended finger.  Presumably, God is endowing Adam with a human soul.  But how exactly is that to happen?  

We should notice that Michelangelo chose not to depict another image of Adam's creation from Genesis: "And the Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul" (2:7).  Michelangelo decided not to show God breathing into Adam's nostrils the breath of life as the source of ensoulment.

So what is it about the image of God flying through the air and stretching out his arm towards Adam lying on the ground that conveys the emergence of a human soul in Adam?  Some neuroscientists have pointed out that one can see a hidden drawing of the human brain in the image of God.  And God's right arm is extended through the prefrontal cortex, which is the part of the cerebral cortex responsible for decision-making, planning, creativity, working memory, and language.  Previously, I have written about how the liberty or freedom to choose between alternatives is a function of the cerebral cortex, under prefrontal control, in its reciprocal interaction with the environment. 

Is This a Hidden Drawing of the Human Brain?

We know that Michelangelo studied human anatomy carefully, and that he dissected human bodies and brains.  We know this from his anatomical drawings.  (Leonardo da Vinci--a contemporary of Michelangelo's--was also a talented anatomist of the brain.)  But of the thousands of Michelangelo's drawings, he destroyed most of them, and only about 600 have survived.  Some of these show drawings of the human skull and brain, but none of them show the exact outline of the cerebral cortex that some neuroscientists have seen hidden in Michelangelo's pictures.  There is certainly no evidence that Michelangelo understood the cognitive functions of the cerebral cortex and the prefrontal cortex.  Seeing a hidden neuroscientific message in Michelangelo's picture seems fanciful.

Nevertheless, we could argue for a modern neuroscientific revision of Michelangelo's picture, in which the image of God could be replaced by the image of the human cerebral cortex.  This would not have to be seen as an atheistic revision of the picture.  Because if the theistic evolutionists (like Francis Collins, Deborah Haarsma, and the last three Catholic popes) are correct, then God works through the natural laws of evolution to execute His creative design.  Some of the theistic evolutionists (like Pope Francis) say that while God works mostly through natural evolution rather than miracles, the creation of the human soul did require an "ontological leap"--a supernatural miracle--that transcended natural evolution.  But as I have argued, there are good reasons to believe that the natural evolution of the primate brain can explain the emergence of the soul in the human brain, so that no miracle was required.  And yet we still have to wonder what properties of the evolved human brain explain the amazing intellectual and emotional capacities of the human mind.

COUNTING NEURONS

Over the past fifteen years, the research of Suzana Herculano-Houzel, a Brazilian neuroscientist now at Vanderbilt University, has shown how this natural evolution of the human brain can be understood as based on the remarkable number of neurons in the human cerebral cortex, as it has emerged from the evolution of the primate brain, and thus we can see that we were created in the image of other primates, just as Charles Darwin suggested in 1871 in The Descent of Man (Gabi et al. 2016; Herculano-Houzel 2016, 2021; Herculano-Houzel and Lent 2005).  I am persuaded by most of what Herculano-Houzel says, although I will identify two points of disagreement with her.

                                                Suzana Herculano-Houzel Counts Neurons

How many neurons are in the human brain?  For many years, the answer from many scientists was 100 billion.  But, surprisingly, when Herculano-Houzel began some years ago looking for the original scientific research that provided evidence for this number, she found nothing.  She discovered that neuroscientists had repeated this number over and over again without realizing that there was no scientific verification for it.  

Moreover, she discovered that scientists had no reliable method for counting brain cells.  The most common method for attempting to do this was stereology: virtual three-dimensional probes are placed throughout thin slices of brain tissue from some part of the brain, then the number of cells within the probes are counted, and finally this is extrapolated to the total number of cells in the entire tissue volume.  The problem is that this works only for tissues with a relatively homogeneous distribution of cells.  In fact, the highly variable density of neurons across different structures of the brain, and even within a single structure, makes stereology impractical for counting the cells in whole brains.

Herculano-Houzel developed a new technique for counting neurons that starts with creating brain soup.  She dissects the brain into its anatomically distinct parts--such as the cerebral cortex, the cerebellum, and the olfactory bulbs.  She then slices and dices each part into smaller portions.  Next, she puts each small part in a tube and uses a detergent that dissolves the cell membranes but leaves the cell nuclei intact.  By sliding a piston up and down in the tube, she homogenizes this brain tissue into a soup in which the nuclei are evenly distributed.  She stains all the cell nuclei blue so that she can count them under a fluorescent microscope.  She then adds an antibody labeled red that binds specifically to a protein expressed in all neuronal cell nuclei, which distinguishes them from other cell nuclei such as glial cells.  Going back to the microscope, she can then determine what percentage of all nuclei (stained blue) belong to neurons (now stained red).  Finally, she can estimate the number of neurons for each structure of the brain.  She has done this in studying the brains of many mammalian animals.

Now she can tell us that the total number of neurons in the whole human brain is not 100 billion but 86 billion.  Of that total, 16 billion are in the cerebral cortex, which includes 1.3 billion neurons in the prefrontal cortex.  The cerebral cortex is the outer covering of the surfaces of the cerebral hemispheres.  The prefrontal cortex covers the front part of the frontal lobe of the cerebral cortex located behind the forehead.

FOUR ADVANTAGES

Comparing the numbers of neurons for the human brain with the numbers for other primate brains and other mammalian brains allows Herculano-Houzel to explain the conundrum of how the human brain can be at once so similar to and yet so different from other animal brains.  She makes four arguments about how the human brain gives human beings four kinds of advantages in their mental abilities: the primate advantage, the human advantage, the advantage of cooking, and the advantage of cultural learning.

Her claim that differences in cognitive capabilities across species can be explained by differences in the absolute numbers of neurons depends on a fundamental assumption.  If neurons are the basic units of brain networks for processing information, and if the networks are structured in similar patterns, then the greater the number of neurons in a network, the greater the capacity of the network for processing information.

The primate advantage.   Not surprisingly, larger brains tend to contain more neurons than smaller brains.  But different groups of animals show different scaling rules in proportioning brain size to number of neurons.  For example, a rodent cortex will have fewer neurons than a primate cortex of similar mass.   Primates always concentrate larger numbers of neurons in the brain than rodents of a similar, or even larger, brain size.

So here a capybara brain of 76 grams has 1.6 billion neurons, while a capuchin monkey brain of 52 grams has 3.7 billion neurons.  Comparison of primates with other mammals shows the same primate advantage:  in primate brains, the neurons are packed more tightly in a similar volume.  As primate brains, human brains have the same primate advantage over other mammals.  Thus, while the number of neurons in the human brain is remarkable, it is not extraordinary, because it falls on the primate scaling line: it's what one would expect for a primate with a body the size of the human body.  As Herculano-Houzel says: "The human brain is just a scaled-up primate brain: remarkable but not special."

One common objection to this is that the bodies of gorillas and orangutans can be as large as human bodies, but the brains of gorillas and orangutans are only about one-third the size of the human brain.  Gorillas and orangutans can weigh about 165 pounds, but their brains have only about 30 billion neurons, in contrast to the 86 billion neurons in the human brain.  Doesn't this show that the human brain is three times larger than what one would expect for a primate with the same size body? 

Herculano-Houzel's answer is that if one excludes the great apes (gorillas and orangutans), the scaling of the human brain in proportion to body size follows the same scaling rule as all other primates.  So the outliers here are not human beings but the great apes: it's not that human brains are too large for their bodies, but that gorillas and orangutans have brains that are too small for their bodies.

She explains this as showing that as primate evolution reaches the outer limits of the primate energy budget--the extra effort to find food--there is a tradeoff between brains and brawn.  More energy for a big body means less energy for a big brain.  The evolutionary history of the great apes shows a tradeoff  favoring big bodies and small brains.  By contrast, the evolutionary history of the human species shows a tradeoff favoring a typically primate slim body but a big brain.

The human advantage.  Herculano-Houzel's counting of neurons has allowed her to see that we human beings have one great advantage over all other animals: "we are the species that owns the largest number of neurons in the cerebral cortex--the part of the brain responsible for finding patterns, reasoning logically, expecting the worst and preparing for it, developing technology and passing it on through culture" (2016, x).  Notice that she is not saying that we have the largest number of neurons in the whole brain.  The African elephant brain has 257 billion neurons, three times our count of 86 billion.  But an amazing 98 percent of the elephant's neurons are in the cerebellum.  Although the elephant's cerebral cortex weighs over 6 pounds, it has only 5.6 billion neurons, far fewer than the 16 billion neurons in the human cerebral cortex weighing 2.6 pounds.  The sperm whale has the largest animal brain--weighing about 18 pounds--but Herculano-Houzel predicts that the number of neurons in the sperm whale's cerebral cortex is probably far fewer than 16 billion.

What Herculano-Houzel says about this human advantage confirms what I have argued about how the human mind or soul can arise from a natural process of emergent evolution in which differences in degree become differences in kind after passing over a critical threshold in the size and complexity of the primate brain.  As a consequence of her research, I can now identify that critical threshold as the remarkably large number of neurons in the human cerebral cortex and particularly in the prefrontal cortex.  Unfortunately, she herself does not see how her research supports the idea of emergent evolution.  That's my first disagreement with her.

In her book chapter on Darwin's Descent of Man--particularly, Darwin's chapter on "Comparison of the Mental Powers of Man and the Lower Animals"--she supports Darwin's claim that human mental powers differ from the mental powers of other animals only in degree and not in kind, and that if this difference were a difference in kind, that would deny his theory of human evolution from lower animals (Herculano-Houzel 2021, 48-49, 51, 61).

Herculano-Houzel does not see that Darwin in The Descent of Man is forced to contradict himself by both affirming and denying that there are differences in kind between human beings and other animals in their mental capacities.  Despite Darwin's explicit statement that humans differ only in degree, not in kind, from other animals, he implicitly recognized differences in kind.  That is to say, Darwin recognized that human beings have some mental traits that other animals do not have at all.

Darwin noted that self-consciousness is uniquely human: "It may be freely admitted that no animal is self-conscious, if by this term it is implied, that he reflects on such points, as whence he comes or whither he will go, or what is life and death, and so forth" (Descent, Penguin edition, 105).  Morality is also uniquely human: "A moral being is one who is capable of comparing his past and future actions or motives, and of approving or disapproving of them.  We have no reason to suppose that any of the lower animals have this capacity. . . . man . . . alone can with certainty be ranked as a moral being" (135).  And language is uniquely human: "The habitual use of articulate language is . . . peculiar to man" (107).

Darwin could implicitly affirm such emergent differences in kind without affirming any radical differences in kind.  Emergent differences in kind can be explained by natural science as differences in kind that naturally evolve from differences in degree that pass over a critical threshold of complexity.  So, for example, we can see the uniquely human capacities for self-consciousness, morality, and language as emerging from the evolutionary increase in the neurons of the primate brain, so that at some critical point in the evolution of our ancestors, the size and complexity of the brain (perhaps particularly in the frontal cortex) reached a point where distinctively human cognitive capacities emerged at higher levels of brain evolution that are not found in other primates.  With such emergent differences in kind, there is an underlying unbroken continuity between human beings and their hominid ancestors, so there is no need to posit some supernatural intervention in nature that would create a radical difference in kind in which there is a gap with no underlying continuity.  

Like Darwin, Herculano-Houzel fails to see how evolutionary science can recognize emergent differences in kind that arise from natural evolution while denying radical differences in kind that would require supernatural miracles.

The advantage of cooking.  If human beings are created in the image of primates, and yet they are unique among the primates because of those 16 billion neurons in the human cerebral cortex, why are human beings the only primate species to evolve such an increase in those neurons?  Herculano-Houzel's answer is that the evolutionary expansion of the human brain was made possible by the human invention of cooking.  Here she adopts the cooking hypothesis of Richard Wrangham in his book Catching Fire: How Cooking Made Us Human (2009).

The energy cost of the human brain is huge.  The brain is only 2 percent of the total body mass, but it consumes on average about 25% of the daily total energy budget for the human body.  On average 3.3 billion molecules of glucose are consumed per human neuron per minute.  6 kilocalories are consumed per billion neurons per day.  And so the more neurons in a brain, the more energy that a brain costs.

The caloric intake from the typical raw food diet of primates is not enough to supply the energy needs of the human brain.  The human controlled use of fire and the invention of cooking about 1.5 million years ago expanded the daily supply of energy to support the evolutionary expansion of the human brain, which can be seen in the fossil record of the huge expansion of the brain from Homo erectus to Homo sapiens.

The slicing and dicing of food and cooking with heat start the process of digesting food before it enters the mouth.  Cooking with heat breaks down the collagen fibers of meat and softens the hard walls of plant cells.  Cooked foods yield 100 percent of their caloric content to the digestive system.  Without cooking, our ancient human ancestors could never have fed their hungry human brains.

In a previous post, I have suggested that this cooking hypothesis for human evolution confirms what Lucretius said about the importance of fire and cooking for the evolutionary emergence of a fully human species.

The advantage of cultural learning.  The controlled use of fire and cooking are technologies that are invented and passed down across the generations by cultural learning.  As Herculano-Houzel observes, this shows us that "plenty of neurons aren't enough," because while having lots of neurons endows a brain with the capacities for complex cognition, turning those capacities into abilities requires cultural learning across an individual lifetime and across many human generations.

As I have indicated in some previous posts, cultural learning is not uniquely human because some other animals have cultural traditions of behavior.  But human beings are unique in their capacity for symbolic culture.

The behavioral inheritance system is the transmission of information among animals through social learning. For example, among some animals (including human beings) mothers transmit food preferences to their offspring, because information about what mother is eating is transmitted either in the womb or through suckling, so that the offspring inherits a preference for that food. More complex forms of social learning come through animal culture. For example, some chimpanzees can discover how to open nuts with a stone, and then pass on this practice within their group so that it becomes a social tradition. Different communities of chimps in Africa have different cultures based on distinctive profiles of traditional practices transmitted by social learning. As opposed to genetic evolution, cultural evolution is not blind but targeted to functional change.

The symbolic inheritance system is uniquely human because it shows the qualitative leap that defines our humanity as based on our capacity for symbolic thought and communication. Other animals can communicate through signs. But only human beings can communicate through symbols. The evolution of human language was probably crucial for the evolution of symbolism. Symbolic systems allow us to think about abstractions that have little to do with concrete, immediate experiences. Symbolic systems allow human beings to construct a shared imagined reality. These symbolic constructions are often fictional and future-oriented. Art, religion, science, and philosophy are all manifestations of human symbolic evolution. 

Herculano-Houzel gives a good account of human cultural evolution as driven by six technological revolutions (2016, 206-213).  But she doesn't explain why the pace of that technological progress has become so rapid over the past 300 years.  I have argued that the best explanation for this accelerated human progress is the symbolic niche construction of Lockean liberalism, which has sustained the freedom for innovation that has made it possible for the Earth today to support a population of over 8 billion people who are living longer and healthier lives on average than has ever been possible.  That is a stunning enhancement of Darwinian survival and reproductive fitness through cultural evolution.

THE SYMBOLIC EVOLUTION OF RELIGIOUS BELIEF IN "METAPHYSICAL ORIGINS"

The evolved cognitive capacity of the human brain for symbolic cultural learning includes a propensity to religious belief, which can include the belief that human beings were created in the image of God, and that this endowed human existence with a supernatural purpose.  Herculano-Houzel fails to take that religious belief seriously as a part of human cultural evolution, and that's my second point of disagreement with her.  She does say that the human brain gives human beings "the ability to ponder our own material and metaphysical origins" (2016, 215).  But she says nothing more about how the religious belief in "metaphysical origins" might be rooted in the evolutionary psychology of the human brain.  In The Descent of Man, in his chapter on the "mental powers of man and the lower animals," Darwin comments on a long list of mental powers, concluding with "belief in God, spiritual agencies, superstitions."  In her commentary on this chapter, Herculano-Houzel is silent about this.

If she had examined that last part of Darwin's chapter on the evolution of the mental powers as leading to religious belief, she would have seen that Darwin anticipates the modern evolutionary psychology of religion as an expression of the human brain's evolved theory of mind or the "hyperactive agency detection device."  Darwin conveys this idea when he says that the earliest manifestation of religious belief is "when anything which manifests power or movement is thought to be endowed with some form of life, and with mental faculties analogous to our own" (117).  Through symbolic cultural evolution this "belief in spiritual agencies" or animism could eventually be expressed in the belief in the existence of an Omnipotent God who is the "Creator and Ruler of the universe" (116, 118).  This is the God depicted in Michelangelo's "Creation of Adam"--the God who created human beings in His image.

The evolutionary science of the brain can explain how this ability for believing in the existence of the Creator God evolved through the genetic evolution of the human cerebral cortex and prefrontal cortex and the symbolic cultural evolution of religious belief in monotheism.  But while some Darwinian psychologists (such as Justin Barrett) see this as showing that Darwinian science is compatible with the truth of believing in God, others (such as Jesse Bering) see this as exposing belief in God as a fictional construction of the evolved human mind. For those like Barrett, religious belief is an adaptive truth. For those like Bering, religious belief is an adaptive illusion.

Thus, we see that Darwinian science cannot resolve the Reason/Revelation debate.  But Darwinian liberalism can support the freedom of thought that promotes that debate.

Part of that Reason/Revelation debate is whether human beings have a natural need to see the purpose for their existence that can only come from believing in the revelation of a divine purpose for human life, or whether natural reason alone can give human life some purpose or meaning.  Some theistic scientists (like Deborah Haarsma) say that in answering our questions about the Universe, science can tell us when and how, but only religion can tell us who and why.

Friedrich Nietzsche thought that the cultural history of the "teachers of the purpose of existence" over thousands of years had changed human nature so that human beings had a culturally acquired need to see some cosmic purpose to their lives.  "Gradually, man has become a fantasizing [phantastischen] animal that has to fulfill one more condition of existence than any other animal: man has to believe, to know, from time to time why he exists; his race cannot flourish without a periodic trust in life--without faith in reason in life" (The Gay Science, sec. 1).  Consequently, Nietzsche observed, "I fear that the animals consider man as a being like themselves that has lost in a most dangerous way its sound animal common sense; they consider him the insane animal, the laughing animal, the weeping animal, the miserable animal" (sec. 224). 

Is this what happens when you have a brain with 16 billion neurons in its cerebral cortex fed by some delicious, cooked meals?

REFERENCES

Darwin, Charles. 2004. The Descent of Man. 2nd edition.  New York: Penguin Books

Gabi, Mariana, et al. 2016. "No Relative Expansion of the Number of Prefrontal Neurons in Primate and Human Evolution." Proceedings of the National Academy of Sciences 113 (no. 34): 9617-9622.

Herculano-Houzel, Suzana. 2016. The Human Advantage: A New Understanding of How Our Brain Became Remarkable.  Cambridge, MA: MIT Press.

Herculano-Houzel, Suzana. 2021. "Remarkable But Not Extraordinary: The Evolution of the Human Brain." In Jeremy M. Desilva, ed., A Most Interesting Problem: What Darwin's 'Descent of Man' Got Right and Wrong About Human Evolution, 46-62.  Princeton: Princeton University Press.

Herculano-Houzel, Suzana, and Richard Lent. 2005. "Isotropic Fractionator: A Simple, Rapid Method for the Quantification of Total Cell and Neuron Numbers in the Brain." Journal of Neuroscience 25: 2518-2521.

Wrangham, Richard. 2009. Catching Fire: How Cooking Made Us Human. New York: Basic Books.