The Darwinian Lockean Liberalism of Goldstein's Mattering Instinct

 

                                               "What's It All About?" Cartoon by Patrick Hardin

The General Diagram for Eric Chaisson's Course on "Cosmic Evolution," Available at His Website.

The Darwinian Lockean Liberalism that I have defended on this blog supports Goldstein's theory of the mattering instinct in four ways.  

The Darwinian evolution of life explains life's self-mattering as resistance to entropy.  Lockean evolutionary psychology explains the human mattering instinct as rooted in self-ownership and religious enthusiasm.  The Lockean evolutionary psychology of morality explains the multiplicity of mattering projects as different rankings of the twenty natural desires of our evolved human nature.  Finally, Darwinian Lockean Liberalism explains how we can rightly condemn some mattering projects as immoral when they assume that mattering is a zero-sum game in which there is not enough mattering to go around.

LIFE'S SELF-MATTERING AS RESISTANCE TO ENTROPY

Patrick Hardin's cartoon shows the biological evolution of complex systems (from the less to the more complex) among vertebrate forms of life--from fish to primates to humans.  Eric Chaisson's diagram shows the cosmic evolution of complex systems from shortly after the Big Bang to the present, which includes purely physical systems as well as biological and cultural systems.  The common underlying theme is the ascent from simple disorder to complex order, or rising complexity.

That ascent to ever more complex order might seem to violate one of the fundamental laws of physics--the Second Law of Thermodynamics--which is the principle that in any natural process, the entropy (the disorder) of the Universe increases, so that energy naturally flows from hotter to colder systems, and not the reverse.  So, for example, a pot of hot soup will tend to cool off over time until it has the same temperature as the surrounding environment; and it will not spontaneously reheat itself.  Similarly, a house of cards will tend to collapse with time; and we can't expect a random collection of playing cards to assemble itself spontaneously into some ordered structure.

But this is true only for "closed systems" in which there is no flow of energy from outside the system.  In "open systems," a flow of energy from outside the system can create and maintain order in the system, and thus resist the tendency to entropy.  You can heat up the pot of soup on a stove.  And you can build a house of cards.  In both cases, you are introducing energy from outside the system to counter the tendency to entropy.  In the one case, you are turning up the gas or electrical heat from the stove.  In the other case, you are exerting your energy in building the house of cards.

The same is true for creating and maintaining the complex order of any system against the tendency to disorder--there must be a flow of energy from outside the system that sustains the order of the system.  And so life on Earth depends on capturing energy (mostly from the Sun through photosynthesis) that can be put to work in sustaining the complex systems of life and resisting entropy.  Animals capture the energy of sunlight through eating and digesting food, and through respiration, animals employ oxygen to release the energy in carbohydrates.  But while being alive is to be in resistance to entropy, eventually entropy wins, and everything that lives must die.

This explains why some evolutionary psychologists have said that "the Second Law of Thermodynamics Is the First Law of Psychology" (Tooby, Cosmides, and Barrett 2003).  Darwinian natural selection is the only known counterweight to the tendency of physical systems to the entropic loss of functional organization.  Organisms with anti-entropic mechanisms that sustain functional organization are more likely to survive and reproduce than organisms that fail to resist entropy.  

For organisms with brains, natural selection will favor psychological mechanisms that resist entropy.  As indicated in Hardin's cartoon, all vertebrates will have psychic mechanisms that incline them to "eat, survive, reproduce"--or better stated, each animal will prioritize its own eating, surviving, and reproducing, which is what Goldstein identifies as the organic message of self-mattering--every organism acts as if its own existence in this world, its persistence and flourishing, matters.  In organisms with brains, with some capacity for mental attention, this self-mattering drives them to acquire information about their environment and to seek out sources of free energy needed to resist entropy, while also avoiding threats to their existence that might hasten their death.

Chaisson's "Epic of Evolution" shows how the Second Law of Thermodynamics Is Also the First Law of Cosmic Evolution.  The ascent of the Cosmos over almost 14 billion years through eight epochs--the Particulate, the Galactic, the Stellar, the Planetary, the Chemical, the Biological, the Cultural, and the Future--moves from simpler systems to more complex systems.  At each level of complexity, these systems require a flow of energy available to work to sustain their complex order against the thermodynamic tendency to disorder.

Chaisson argues that this correlation between energy and complexity allows us to use "energy rate density" as the universal metric of complexity for all complex systems--from physical systems to biological systems to cultural systems.  Energy rate density is defined as "the amount of energy passing through a given system per unit time per unit mass" (Chaisson 2006:293).  This can be quantified as the number of ergs per second per gram (erg/s/g).  

By this measure, human beings are more complex than stars like the Sun because the energy rate density for a human being is much higher than for the Sun.  And within human beings, their brains are one of the most complex systems in the Universe.  Although our brain occupies only about two percent of our body's mass, our brain uses almost twenty percent of our body's total energy intake because of the high metabolism required to maintain the electrical activity of about 86 billion neurons with about 100 trillion synaptic connections (Chaisson 2006:295).

Although Goldstein does not cite Chaisson's work, she agrees with his central idea about energy rate density as the metric of complexity: "All life, all flourishing, depends on capturing energy (from sunlight or food) and applying it in local anti-entropic resistance.  And the more complicated the system, then the more ways for it to be disordered, and hence the more resistance required.  Again, our brains are the most complicated objects yet discovered in the universe and, not coincidentally, require a lot of energy" (57).

THE HUMAN MATTERING INSTINCT AS ROOTED IN SELF-OWNERSHIP OR DIVINE OWNERSHIP

The unique complexity of the human brain has created an emergent difference in kind from other animal brains, such that human beings are unique in their mattering instinct.  Every animal is driven by an organic mandate that ensures it matters to itself--that it pays attention to itself and to what it needs to do to secure its survival and flourishing.  But we human beings are the only animals for whom it is not sufficient that we subjectively feel that we matter to ourselves, because we must persuade ourselves that we truly objectively deserve to matter.

In persuading ourselves that we truly matter, we must appeal to one of two kinds of the mattering instinct of our evolutionary psychology--one grounded in divine ownership and the other grounded in self-ownership.  The natural human experience of religious transcendence--of being possessed by religious enthusiasm--can persuade us that we belong to God because He created us to serve His purposes, and therefore we matter because we matter to God.  In that case, we are transcenders on Goldstein's Mattering Map.

Or the natural human experience of self-ownership can persuade us that since we naturally own ourselves--our bodies and our minds--we are naturally free to pursue whatever conception of happiness or human flourishing that is best suited to our individual temperament, circumstances, and talents, and therefore our life matters because we are striving for some kind of moral or intellectual excellence in our life.  In that case, we are either socializers, heroic strivers, or competitors on the Mattering Map. 

 

In his Second Treatise, Locke seems to support the transcenders by grounding his law of nature in the "workmanship" of God in creating human beings:

The State of Nature has a Law of Nature to govern it, which obliges every one: And Reason, which is that Law, teaches al Mankind, who will be consult it, that being all equal and independent, no one ought to harm another in his Life, Health, Liberty, or Possessions. For Men being all the Workmanship of one Omnipotent, and infinitely wise Maker; All the Servants of one Sovereign Master, sent into the World by his order and about his business, they are his Property, whose Workmanship they are, made to last during his, not one another's Pleasure. And being furnished with like Faculties, sharing all in one Community of Nature, there cannot be supposed any such Subordination among us, that may Authorize us to destroy one another, as if we were made for one another's uses, as the inferior ranks of Creatures are for ours (para. 6).

Locke believed that the workmanship argument would require a rational theology that could prove the existence of God.  From “the idea of ourselves as understanding, rational creatures,” we would have to infer “the idea of a supreme Being, infinite in power, goodness, and wisdom, whose workmanship we are."  Through an anthropomorphic analogy, we could project from the idea of our own minds and other human minds the idea of a Divine Mind.  Thus, man would create God in man’s image.  But then Locke admitted that having the idea of God in one’s mind does not prove God’s real existence (ECHU, IV.3.18; IV.3.27; IV.10.1; IV.10.7; IV.10.19; IV.11.1).

Similarly, some evolutionary psychologists—such as Justin Barrett and Jesse Bering--have argued that the natural evolution of religious belief is rooted in the propensity of the human mind to detect rational agency in humans and other animals and then to infer a supernatural intelligent agency analogous to that of human minds.  But this anthropomorphic analogy between human and divine minds is dubious, and even if this explained the natural evolution of the idea of God in the human mind, that would not prove the existence of God.

This led Locke to conclude that believing in the existence of God is ultimately not a matter of reason but of faith.  And since “faith is not knowledge,” we cannot know what the true religion is (Locke, 1870, pp. 94-96; 1997, pp. 248-50; ECHU, IV.17-18). 

Since he doubted that reason could prove God’s existence in support of the workmanship argument, Locke developed the self-ownership argument that would provide a purely natural ground for his law of nature.  He wanted to appeal to a rational theology of divine workmanship, but if that failed, he could fall back onto his natural self-ownership argument.  These two tracks—God and nature--are suggested by Locke’s repeated appeals to “the Laws of God and Nature” (FT, 56, 124; ST, 60, 66, 90, 93, 142, 195).  The “fixed and permanent rule of morals” could be “firmly rooted in the soil of human nature,” and human nature could be understood as created by “nature or God” (1997, p. 125).  Notice that the creative source of human nature is nature or God.

Locke affirms individual self-ownership in his chapter on property in the Second Treatise:

Though the Earth, and all inferior Creatures be common to all Men, yet every Man has a Property in his own Person. This no Body has any Right to but himself. The Labour of his Body, and the Work of his Hands, we may say, are properly his. Whatsoever then he removes out of the State that Nature hath provided, and left it in, he hath mixed his Labour with, and joyned to it something that is his own, and thereby makes it his Property. (para. 27)

From all which it is evident, that though the things of Nature are given in common, yet Man (by being Master of himself), and Proprietor of his own Person, and the Actions or Labour of it) had still in himself the great foundation of Property. (para. 44)

Here the foundation of Locke's political philosophy of natural rights is not God's ownership of the world and His rule by natural law, but rather the idea that human beings have natural rights because they are self-owners. Moreover, it is this natural autonomy of human beings, rather than their natural subordination to God, that informs the modern understanding of human rights.

Evolutionary science can show that the evolved psychology of ownership is rooted in self-ownership.  The human brain has an evolved interoceptive sense of owning the body that supports self-ownership and the ownership of external things as extensions of the self-owning self.  In this way, evolutionary neuroscience supports a Lockean liberal conception of equal natural rights rooted in natural self-ownership.  We can see how this sense of each person’s self-ownership arises in the evolved neuroanatomy of the brain to serve the survival and well-being of the human animal.  We can understand this as expressing interoception—the neural perception of the state of the body.

HUMAN FREEDOM AFFIRMS THE MULTIPLICITY OF MATTERING PROJECTS

In the Essay Concerning Human Understanding, Locke says that in all of their actions, all human beings are moved to satisfy their natural human desires, and while there are many natural desires--I have identified twenty--they are all part of the human pursuit of happiness.  Human beings differ, however, in how they rank the natural desires.  For example, some human beings rank the natural desire for religious transcendence above all, while others rank the natural desire for intellectual understanding as the greatest pleasure.  So while there is no single summum bonum or highest good for all people, there is a single summum bonum for each person, and the pursuit of that highest good will be that person's mattering project (ECHU, 2.21.31-73).

If every human being is free to pursue his summum bonum, then every person's life matters.  The Lockean liberal regimes promote that freedom.  Countries that rank high on the "Human Freedom Index" tend to be countries that secure the widest pursuit of happiness and the multiplicity of mattering projects.  That is confirmed by the patterns of immigration: generally, people want to leave the less free societies and immigrate to the free societies.  Human beings vote with their feet for freedom.

HUMAN FREEDOM DENIES THE ZERO-SUM MATTERING PROJECTS

And yet a free society cannot tolerate all mattering projects.  It cannot tolerate those immoral mattering projects in which one person's sense of mattering comes from denying the mattering of others.  For example, when Frank Meeink was seventeen-year-old neo-Nazi skinhead, he was sent to prison for three years for kidnapping and torturing a teenage boy whom he believed to be a SHARP (a Skinhead Against Racial Prejudice), and thus a traitor to the neo-Nazi movement.  Meeink's mistake was in thinking that mattering is a zero-sum game in which one person's gain is another person's loss because there isn't enough mattering to go around.

On the contrary, the fundamental moral principle in a Lockean liberal social order is that all lives matter because there really is enough mattering to go around, as Goldstein argues (271-292).  Locke conveyed this thought in Some Thoughts Concerning Education when he advised parents about the importance of instilling the virtue of "civility" in their children, so that they would show "general good will and regard for all people," knowing that we are "not to think meanly of ourselves and not to think meanly of others" (secs. 141, 143).

REFERENCES

Chaisson, Eric. 2006. Epic of Evolution: Seven Ages of the Cosmos. New York: Columbia University Press.

Locke, John. 1870. Four Letters on Toleration. London: Ward, Lock, and Tyler.

Locke, John. 1997. Political Essays. Ed. Mark Goldie. Cambridge: Cambridge University Press.

Tooby, John, Leda Cosmides, and H. Clark Barrett. 2003. "The Second Law of Thermodynamics is the First Law of Psychology." Psychological Bulletin 129:858-865.

The Darwinian Lockean Liberalism of Natural Religion

In this season of the year, our greetings of "Merry Christmas" and "Happy Holidays" acknowledge our natural human propensity to religious beliefs and rituals, while also acknowledging that in the modern liberal social orders in which many of us live today, we respect religious liberty and toleration.  "Merry Christmas" doesn't favor any one Christian tradition over any other.  And "Happy Holy Days" recognizes that there are some non-Christian religious observances during this season--particularly, the Jewish festival of Hanukkah.

The Darwinian Lockean Liberalism that I have defended explains the naturalness of religion as rooted in our evolved human nature.  It also explains why we need religious liberty and toleration so that all individuals have the equal liberty to pursue their natural desire for religious experience in their own way.

My position has provoked lots of criticisms, of which two are most prominent.  The first is that Darwinian Lockean Liberalism is incoherent insofar as Darwinian atheism denies the Christian foundations of Lockean Liberalism.  The second is that Lockean religious liberty and toleration denies the truth of Christian Integralism (Catholic or Protestant) that there is one true church--the true Christian Church established by Jesus Christ--and that this Christian Church can rightly use the secular authority of government to enforce the Orthodoxy of that Church.

I have previously responded to these two criticisms (here and here).  But after thinking more about these issues, I have decided to lay out a slightly revised version of my previous responses.

Various authors have countered my position with a syllogistic rebuttal (Dilley, 2013; Holloway, 2006; West, 2006).  I will call this “Dilley’s Syllogism” because Stephen Dilley formulated it in his Introduction to his edited book Darwinian Evolution and Classical Liberalism:

Classical (Lockean) liberalism is founded on Christianity.

Darwinism denies Christianity.

Therefore, Darwinism denies classical (Lockean) liberalism.

The conclusion of this syllogism is false, because the major premise is only partly true, and the minor premise is totally false.

The major premise has been asserted by those of my critics who are proponents of what they call “Christian classical liberalism” or “theistic classical liberalism” (Dilley, 2013, pp. 19, 23, 158-59).  I have inserted “Lockean” into the syllogism because these critics generally appeal to Locke as “the quintessential classical liberal” (Dilley, 2013, p. 198).  The only doctrinal teaching of Christianity that they mention as supporting Lockean classical liberalism is the idea of imago Dei: that all human beings have been created in the image of God (as declared in Genesis 1:26-27) seems to endow them with the equal moral dignity that supports the classical liberal teaching that all human beings are created equal in their moral dignity as equally endowed by God with natural rights (Dilley, 2013, p. 11). 

Locke seemed to adopt this idea in speaking about the law of nature as grounded in the nature of human beings as God’s “workmanship”:

Reason, which is that Law, teaches all Mankind, who will but consult it, that being all equal and independent, no one ought to harm another in his Life, Health, Liberty, or Possessions.  For Men being all the Workmanship of one Omnipotent, and infinitely wise Maker; All the Servants of one Sovereign Master, sent into the World by his order and about his business, they are his Property, whose Workmanship they are, made to last during his, not one another’s Pleasure (ST, 6).

Locke identified this idea of men being God’s property because they are his workmanship with man being created in God’s image, in the sense that all members of the human species were created as “intellectual creatures,” which gave them dominion over the “inferior creatures,” but without giving any human being dominion over any other human being, because all men were equal in having a human mind that was a likeness to the Mind of God (FT, 30, 39, 52-54, 85-86; ST, 56).

But Locke also claimed that natural rights were rooted in every man’s self-ownership (ST, 27).  Now, as Peter Laslett (1970, p. 100) observed, this principle of human self-ownership “almost contradicts his principle that men belong to God, not themselves.”  “Almost”?  Can men both belong to themselves and belong to God?  I have argued that evolutionary neuroscience can explain the human experience of self-ownership as rooted in the interoceptive capacity of the embodied brain.  But the human experience of being owned by God might be harder to explain scientifically.

The apparent contradiction between Locke’s principle of self-ownership and his principle of divine ownership can be resolved by seeing that Locke made what Michael Zuckert has called a “two-track argument,” in which “one track is theistic, the workmanship argument, an argument of natural theology; the other track is the appeal to self-ownership” (Zuckert, 2002, pp. 4-5; 2005, p. 431).  Locke believed that the workmanship argument would require a rational theology that could prove the existence of God.  From “the idea of ourselves as understanding, rational creatures,” we would have to infer “the idea of a supreme Being, infinite in power, goodness, and wisdom, whose workmanship we are” (ECHU, IV.3.18).  Through an anthropomorphic analogy, we could project from the idea of our own minds and other human minds the idea of a Divine Mind.  Thus, man would create God in man’s image (ECHU, IV.3.27; IV.10.1).  But then Locke admitted that having the idea of God in one’s mind does not prove God’s real existence (ECHU, IV.10.7; IV.10.19; IV.11.1).

Since he doubted that reason could prove God’s existence in support of the workmanship argument, Locke developed the self-ownership argument that would provide a purely natural ground for his law of nature.  He wanted to appeal to a rational theology of divine workmanship, but if that failed, he could fall back onto his natural self-ownership argument.  These two tracks—God and nature--are suggested by Locke’s repeated appeals to “the Laws of God and Nature” (FT, 56, 124; ST, 60, 66, 90, 93, 142, 195).  The “fixed and permanent rule of morals” could be “firmly rooted in the soil of human nature,” and human nature could be understood as created by “nature or God” (1997, p. 125).  Notice that the creative source of human nature is nature or God.

Consequently, the major premise of Dilley’s Syllogism is only partly true.  Yes, Locke’s classical liberalism can be grounded in the Christian doctrine of creation in the image of God as supporting the workmanship argument.  But Locke suggested that reason can neither prove nor disprove creationist theology.  And that led him to appeal to the self-ownership principle as a purely naturalistic argument that did not require any theological assumptions.  Another way of saying this is that Locke left the Reason/Revelation debate open, believing that neither side can refute the other.  And so, he often invited his readers to consider both what “Reason” taught them by their natural experience and what “Revelation” taught them through their reading of the Bible (ST, 25).

The minor premise of Dilley’s Syllogism—Darwinism denies Christianity—assumes that the Darwinian scientist believes that scientific reason can refute Christian revelation and thus supports atheism.  But even if this is true for some Darwinian scientists, it is not true for all--not even for Darwin himself.  Moreover, Darwinian evolutionary science recognizes that there is a natural desire for religious understanding, and so atheism is contrary to our evolved human nature.  But even though religious belief is natural for most human beings, what they believe about the supernatural will be determined by faith rather than reason.  And since religious believers can never reach agreement about the content of their faith, they must accept the fact of religious pluralism and recognize how that religious pluralism dictates the religious toleration that secures religious liberty.

Of course, there are Darwinian atheists.  Richard Dawkins, for example, has said that “I could not imagine being an atheist at any time before 1859, when Darwin’s Origin of Species was published.”  He thinks the Argument from Design has always been the best of the arguments for the existence of God, because the complexity of the living world appears to be the work of an intelligent designer—just as William Paley’s watch implied the existence of a watchmaker—and so we might infer that God is the Intelligent Designer of the living world.  David Hume rightly criticized this reasoning as illogical because it rests on a false analogy between human intelligent design and divine intelligent design.  We have all seen human intelligent designers at work as part of our ordinary human experience.  But we have never seen a Divine Intelligent Designer creating everything out of nothing.  This is not part of our ordinary human experience.  It is fallacious, therefore, to use apparent design in nature as evidence for the existence of God.  But even if Hume was right about this, Dawkins has observed, Hume did not offer any alternative explanation for apparent design in nature.  It was only in 1859, when Darwin showed how evolution by natural selection could explain complex biological design, that “Darwin made it possible to be an intellectually fulfilled atheist” (Dawkins, 1986, pp. 5-6).

And yet Darwin himself denied that his theory of evolution promoted atheism.  Consider what he said about “the Creator” in the last two paragraphs of The Origin of Species.  He rejected the common “view that each species has been independently created,” and he proposed instead that “it accords better with what we know of the laws impressed on matter by the Creator, that the production and extinction of the past and present inhabitants of the world should have been due to secondary causes, like those determining the birth and death of the individual.”  Then, in his famous last sentence, he spoke of the “grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one,” and that “from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved” (1936, pp. 373-74).

Here we see that Darwin adopted the medieval Scholastic metaphysics of “dual causality” in distinguishing supernatural primary causes and natural secondary causes (Maurer, 2004).  The Creator did not miraculously create each species of life separately.  But He did originally exercise primary causality in impressing the laws of nature on matter and breathing life into a few forms or into one.  Then, from that simple beginning, the Creator allowed all the forms of life to emerge through the secondary causes of the natural evolutionary process.

At this point in his life, Darwin was what today we would call a “theistic evolutionist” or “evolutionary creationist”—someone who believes that the existence of God as the Creator is compatible with evolutionary science.  Indeed, Darwin said that it was “absurd to doubt that a man may be an ardent Theist and an evolutionist.”  And even when, towards the end of his life, he became an agnostic, he insisted: “In my most extreme fluctuations, I have never been an atheist in the sense of denying the existence of God” (1879; 1969, pp. 92-96). 

In the creation/evolution debate among Christians today, many Christian thinkers—such as Francis Collins, Deborah Haarsma, Darrel Falk, Alvin Plantinga, and Justin Barrett—have defended evolutionary creationism in arguing that, just as Darwin said, one can be both a theist and an evolutionist (Collins, 2006; Stump, 2007).  Remarkably, even the “young-Earth creationists,” who believe in the literal six-days-creation story in Genesis and a 6,000-year-old Earth, concede that Darwin’s Origin of Species refuted the traditional belief that God specially created all species of life, because they agree that all species emerged through evolution by natural selection.  But they also insist that God had to specially create all the “kinds” of animals and plants, so that the evolution of species could unfold within the limits of those “kinds” (with “kinds” corresponding to the taxonomic level of “families”) (Wood, 2008, 2011; Wood and Murray, 2003; Ham, 2017, pp. 14-26).   This resembles what Darwin said about the Creator breathing life into “a few forms or into one,” from which all species could then evolve by natural selection.

Darwin and the evolutionary creationists agree with Locke that religious belief is natural for human beings because they are naturally inclined to infer from their knowledge of their own minds and the minds of others that there must be a divine mind that exercises a supernatural intelligent agency analogous to the natural intelligent agency of human minds.  Darwin observed that when “conceiving this immense and wonderful universe, including man with his capacity of looking far backwards and far into futurity,” he “felt compelled to look to a First Cause having an intelligent mind in some degree analogous to that of man,” which made him a theist (1969, pp. 92-93).  

Similarly, some evolutionary psychologists—such as Justin Barrett and Jesse Bering--have argued that the natural evolution of religious belief is rooted in the propensity of the human mind to detect rational agency in humans and other animals and then to infer a supernatural intelligent agency analogous to that of human minds (Barret, 2004; Bering, 2011).  But as we have seen, this anthropomorphic analogy between human and divine minds is dubious, and even if this explained the natural evolution of the idea of God in the human mind, that would not prove the existence of God.

This led Locke to conclude that believing in the existence of God is ultimately not a matter of reason but of faith.  And since “faith is not knowledge,” we cannot know what the true religion is (Locke, 1870, pp. 94-96; 1997, pp. 248-50; ECHU, IV.17-18).  Consequently, political rulers cannot coercively enforce belief in the religious orthodoxy of the true church, because religious believers cannot agree on what that orthodoxy is.  “Every man is orthodox to himself,” Locke observed in the Letter Concerning Toleration.  And “every church is orthodox to itself” (2010, pp. 7, 21, 38).  The simple fact of religious pluralism—that religious believers cannot agree on religious orthodoxy—supports Locke’s liberal argument for religious liberty and toleration of all religious sects that inflict no injury on others.  Religious liberty and religious pluralism create a free marketplace of religion in which religious movements must compete for adherents.  Those religious groups that succeed in satisfying the natural desire for religious understanding gain a larger share of the religious market (Seabright, 2024).

The mistake of the Christian Integralists (both Catholic and Protestant) in rejecting Lockean religious liberty and toleration and affirming Christian Theocracy (or Christian Nationalism) is their failure to see how any theocratic attempt to suppress religious pluralism must be oppressively unjust and also contrary to the religious voluntarism practiced by the early Christian Churches.

We can see then how a Darwinian Lockean Liberalism can explain natural religion and can secure the religious liberty and toleration that respect religious pluralism and allow every individual to satisfy his natural desire for religious understanding in his own way, while allowing all others the same religious liberty.

Merry Christmas and Happy Holidays!

REFERENCES

Barrett, J. 2004. Why Would Anyone Believe in God? Lanham, MD: Rowman and Littlefield.

Bering, J. 2011. The Belief Instinct: The Psychology of Souls, Destiny, and the Meaning of Life. New York: W. W. Norton.

Collins, F. S. 2006. The Language of God. New York: Free Press.

Darwin, C. 1879. Letter to John Fordyce, May 7. Cambridge, UK: Darwin Correspondence Project, Letter No.: DCP-LETT-12041.

Darwin, C. 1936. The Origin of Species & The Descent of Man. New York: Random House, The Modern Library.

Darwin, C. 1969. The Autobiography of Charles Darwin. Ed. N. Barlow. New York: W. W. Norton.

Dilley, S., ed. 2013. Darwinian Evolution and Classical Liberalism: Theories in Tension. Lanham, MD: Lexington Books.

Ham, K. 2017. "Young-Earth Creationism." In J. B. Stump, ed., Four Views on Creation, Evolution, and Intelligent Design. Grand Rapids, MI: Zondervan.

Holloway, C. 2006. The Right Darwin? Evolution, Religion, and the Future of Democracy. Dallas: Spence Publishing.

Laslett, P. 1970. Introduction. In: John Locke, Two Treatises of Government: A Critical Edition with an Introduction and Apparatus Criticus, by Peter Laslett. Second edition. Cambridge: Cambridge University Press, pp. 3-152.

Locke, J. 1870. Four Letters on Toleration. London: Ward, Lock, and Tyler.

Locke, J. 2010. A Letter Concerning Toleration and Other Writings, M. Goldie, ed. Indianapolis: Liberty Fund.

Maurer, A. 2004. "Darwin, Thomists, and Secondary Causality." The Review of Metaphysics 57: 491-514.

Seabright, P. 2024. The Divine Economy: How Religions Compete for Wealth, Power, and People. Princeton: Princeton University Press.

Stump, J. B., ed. 2017. Four Views on Creation, Evolution, and Intelligent Design. Grand Rapids, MI: Zondervan.

West, J. G. 2006. Darwin's Conservatives: The Misguided Quest. Seattle, WA: Discovery Institute Press.

Wood, T. C. 2008. "Species Variability and Creationism." Origins Number 62: 6-24.

Wood, T. C., and M. J. Murray. 2003. Understanding the Pattern of Life: Origins and the Organization of the Species. Nashville, TN: Broadman & Holman.

Zuckert, M. 2002. Launching Liberalism: On Lockean Political Philosophy. Lawrence: University Press of Kansas.

Zuckert, M. 2005. "Locke-Religion-Equality." The Review of Politics 67: 419-431.

Did C. S. Lewis's Natural Desire for Joy Show the Supernatural Reality of God and Heaven? The Evolutionary Psychology of Religious Experience

The end of the movie--but not the stage play--"Freud's Last Session" suggests that Freud has been persuaded by Lewis's Argument from Desire for the reality of Heaven.  

On his train back to Oxford, Lewis looks at the book that Freud had slipped into his coat pocket.  It's Freud's copy of Lewis's book The Pilgrim's Regress (Grand Rapids, MI: William Eerdmans, 2014, originally published in 1933).  Lewis sees that Freud has written inside the book "from error to error, one discovers the entire truth."  Lewis smiles as his train enters a tunnel, and then the movie fades out.

The quotation is so enigmatic that most viewers will be confused as to what it means, although they can see that Lewis is pleased or amused by it.  As I noted in a previous post, the quotation is an altered version of a quotation from Francis Bacon: "Truth emerges more readily from error than from confusion."

Anyone who has read The Pilgrim's Regress could see how this applies to the book.  It's the story of the pilgrim John whose journey to an enchanting island takes him through adventures with a series of people, most of whom are allegorical representations of various errors that he must avoid.  In the "Afterword to the Third Edition" of the book, Lewis explained it as a depiction of his own experience of intense Desire as he progressed "from 'popular realism' to Philosophical Idealism; from Idealism to Pantheism; from Pantheism to Theism; and from Theism to Christianity" (231).  In later writings--particularly, in Surprised by Joy (1955)--Lewis called this Desire Joy, and he said that "in a sense the central story of my life is about nothing else" (17).

THE ARGUMENT FROM THE EXPERIENCE OF JOY

In the "Afterword" and in Surprised by Joy, Lewis indicated that there is a peculiar mystery about the object of this Joyful Desire.  When people feel this Desire, they think they know what they are desiring.  A child looks wistfully at a distant hillside and thinks he would be happy "if only I were there."  Or he reads a fairy tale and thinks he would be happy if that fairy-tale land really existed.  A man in love thinks he would be happy if he possessed the perfect beloved.  Or a man longs to travel to foreign lands, and he thinks he would be fulfilled if he could see visit those places.  Or a man driven by ambition to gain great status and power thinks he would be happy if he could satisfy that ambition.  Or a man absorbed by his studies in philosophy or science thinks he would be fully satisfied if only he could achieve a full intellectual understanding of his subject.  

Lewis claims that by his own experience he has proven all of these impressions to be wrong.  Every one of these supposed objects for this Joyful Desire is inadequate because having any of these objects would not satisfy the Desire.

"It appeared to me therefore that if a man diligently followed this desire, pursuing the false objects until their falsity appeared and then resolutely abandoning them, he must come out at last into the clear knowledge that the human soul was made to enjoy some object that is never fully given--nay, cannot even be imagined as given--in our present mode of subjective and spatio-temporal experience.  This Desire was, in the soul, as the Siege Perilous in Arthur's castle--the chair in which only one could sit.  And if nature makes nothing in vain, the One who can sit in this chair must exist" (PR, 237).

Lewis concludes that the One who can sit in that chair is God.  So our search for Joy can be satisfied by nothing in the natural world but only by our entering the supernatural Heaven where we will be united with God.  Freud was perhaps suggesting his agreement--"from error to error, one discovers the entire truth."

But is this really the truth?  Has Lewis made a cogent argument for this conclusion?  John Beversluis (C. S. Lewis and the Search for Rational Religion) has made a good case for saying No.  And I agree with Beversluis that Lewis's desire for Joy--for religious transcendence--is not evidence for the transcendent reality of God and Heaven.  

But I disagree with Beversluis's claim that this is not a natural desire at all.  There are good reasons for believing that the desire for religious transcendence is one of the 20 natural desires of our evolved human nature, although the natural reality of this desire neither proves nor disproves the supernatural reality of its transcendent object.

As Beversluis indicates, Lewis's Argument from Desire can be framed schematically as either deductive or inductive.    The deductive version goes like this (Beversluis, 41):

1.  Nature makes nothing in vain, that is, every natural desire has an object that can satisfy it.

2.  Joy is a natural desire, but not for any natural object because no object in the natural world can satisfy it.

3.  Therefore, Joy is a desire for an object beyond the natural world and that object must exist.

Lewis suggested this deductive form when he used the word "must" in his conclusion: "And if nature makes nothing in vain, the One who can sit in this chair must exist."

The inductive version of the argument goes like this (Beversluis, 43):

1.  Many natural desires have objects that can satisfy them.

2.  Joy is a natural desire for a kind of satisfaction that no object in the natural world can satisfy.

3.  Therefore, Joy is a desire for an object beyond the natural world and that object probably exists.

Lewis suggested this inductive form when he used words like "a pretty good indication" and "most probable explanation."   In "The Weight of Glory," he wrote:

"Do what they will, then, we remain conscious of a desire which no natural happiness will satisfy.  But is there any reason to suppose that reality offers any satisfaction to it?  'Nor does the being hungry prove that we have bread.'  But I think it may be urged that this misses the point.  A man's physical hunger does not prove that man will get any bread; he may die of starvation on a raft in the Atlantic.  But surely a man's hunger does prove that he comes of a race which repairs its body by eating and inhabits a world where eatable substances exist.  In the same way, though I do not believe (I wish I did) that my desire for Paradise proves that I shall enjoy it, I think it a pretty good indication that such a thing exists and that some men will.  A man may love a woman and not win her; but it would be very odd if the phenomenon called 'falling in love' occurred in a sexless world" (The Weight of Glory, New York: HarperCollins, 2001, pp. 32-33, italics added).

In Mere Christianity, he wrote:

"Creatures are not born with desires unless satisfaction for those desires exists.  A baby feels hunger: well, there is such a thing as food.  A duckling wants to swim: well, there is such a thing as water.  Men feel sexual desire: well, there is such a thing as sex.  If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world" (120, italics added). 

In his play (p. 16), but not in his screenplay for the movie, Mark St. Germain has Lewis repeat this passage but without the sentence on sexual desire. 

Beversluis correctly observes that Lewis's argument--in both its deductive and inductive forms--fails.  The deductive argument fails because it begs the question at issue: the major proposition assumes that "every natural desire has an object that can satisfy it," but that's what Lewis needs to prove.

The inductive argument rests on a false analogy: it's not at all clear that the desire for supernatural transcendence is a natural desire of the same kind as the natural human desires for food and sex or the duckling's natural desire to swim.  From the fact that the natural desires for food, sex, and swimming have natural objects that can satisfy them, it does not follow that a natural desire for a supernatural bliss probably shows that there really is a supernatural object that can satisfy it.

The natural desire for religious transcendence is different in kind from all other natural desires, because it is the only natural desire that aims at a supernatural end that cannot be achieved in the natural world.  Beversluis contends that this desire is so radically different from all other natural desires that it should not be considered a natural desire at all.  Here is where I disagree with him.

Although Lewis does not explain what he means by natural desires, his examples--human desires for food and sex and a duckling's desire to swim--suggest that he means innate desires that arise spontaneously in all normal members of a species as part of their evolved nature.  Natural desires are evolutionary adaptations that are necessary for the survival and reproductive success of a species.  But, Beversluis observes, Lewis's Joy does not seem to be biologically instinctive in this way, because it is not necessary for the survival or reproductive success of the human species.  Moreover, if it were an instinctive desire of evolved human nature, one would expect to find evidence that it is universal for all human cultures throughout human history; but Lewis has not provided such evidence (45, 52-53).

LEWIS ON THE NATURAL AND SUPERNATURAL EVOLUTION OF RELIGIOUS EXPERIENCE

Lewis does suggest, however, an evolutionary explanation of religious experience that could be judged in the light of the modern evolutionary psychology and cognitive science of religion.  Showing the influence of Rudolf Otto's The Idea of the Holy (London: Oxford University Press, 1923), Lewis sketches the evolutionary development of religion through four stages in the Introduction to The Problem of Pain (16-25).  The first stage is what Otto called the experience of the Numinous--the feeling of dread and awe in the experience of the uncanny.  Otto coined the word "numinous" from the Latin word numen for "divinity."  According to Lewis, this arose first among prehistoric human beings.  "Now nothing is more certain than that man, from a very early period, began to believe that the universe was haunted by spirits" (17).  This dreadful and awful feeling of ghostly invisible spirits was "the seed of religious experience" (God in the Dock, 189).

The second stage in religious evolution came with the human feeling that there is a moral law--the sense that we "ought" or "ought not" to engage in certain kinds of conduct.  Human beings agreed in prescribing this moral law although they often failed to obey it.

The third stage in religious development was when human beings identified the Numinous Power as the guardian of that moral law.  The Jews in the Hebrew Bible show this identification of the Numinous with the moral law:  God is righteous and loves righteousness.

Finally, in New Testament Christianity, a man is born who claims to be the son of, or the same as, that Numinous Power who is also the giver of the moral law.  The teaching of the New Testament--the incarnation of Jesus as both human and divine and the promise that his sacrificial death and resurrection will redeem sinful human beings so that they can be resurrected to eternal life in Heaven--is the completion of all previous religious development.  Because now, for the first time in history, human beings can satisfy their deepest natural desire for supernatural happiness by being resurrected after death to eternal life in the presence of God, and thus return to the true home from which they came.

Lewis suggests that this evolution of religious experience through four stages could be explained in two ways.  It could be a fully natural evolution of human religious experience through four stages of the biological and cultural evolution of the human mind.  Or it could be that at each of these four stages of natural evolution, there was some human experience of a supernatural Revelation from God.

As I have indicated in some previous posts, Lewis was a theistic evolutionist, who thought there was no conflict between the natural science of evolution and the supernatural Revelation of Christianity, because Christians should see that God could carry out His will through the natural process of evolution along with some supernatural interventions into natural history (such as the Incarnation of Christ).

So, when prehistoric human ancestors first began to experience the Numinous--feeling dread and awe in the belief that "the universe was haunted by spirits"--Lewis says there are only two possible explanations:

"There seem, in fact, to be only two views we can hold about awe.  Either it is a mere twist in the human mind, corresponding to nothing objective and serving no biological function, yet showing no tendency to disappear from that mind at its fullest development in poet, philosopher, or saint: or else it is a direct experience of the really supernatural, to which the name Revelation might properly be given" (Mere Christianity, 20-21).

Presumably, most readers of this passage will dismiss the first alternative--"a mere twist in the human mind"--as unsatisfactory, and thus they might think there is no good alternative to Revelation as an explanation.  But here Lewis displays one of his favorite rhetorical tricks--the false dichotomy.  Anyone who knows anything about the evolutionary psychology of religion will know that to explain the appearance of the first religious experience of a world "haunted by spirits" in human evolution, we are not forced to choose between "a mere twist in the human mind" that is inexplicable and a Revelation that erupts miraculously in human experience. 

THE EVOLUTIONARY PSYCHOLOGY OF RELIGIOUS EXPERIENCE

In saying that a mental capacity for religious experience would be "serving no biological function," Lewis adopted the position of Alfred Russel Wallace, who agreed with Charles Darwin in developing the theory of evolution by natural selection, but who denied that this could explain the higher mental and moral capacities of human beings.  Wallace argued that since the mental power for religious experience does not serve any biological need for survival and reproduction, this mental power could not have evolved by natural selection.  So natural selection shaped the "animal nature" of human beings but not their "spiritual nature," which must arise from "the unseen universe of Spirit."

But now the evolutionary psychology of religion--as developed by Justin Barrett, Jesse Bering, and others--can show how although the propensity to religious experience has not evolved directly to serve a biological function, it has evolved as a byproduct of innate mental mechanisms directly shaped by biological evolution for detecting agency--for identifying objects in the environment (particularly, animals and other human beings) that move themselves for the sake of goals as guided by mental states like beliefs and desires.  Once such agents have been detected, the human capacity for mind-reading generates predictions about the mental states of these agents and how these mental states might direct their actions.  As naturally social animals whose survival and reproductive fitness has depended on a subtle negotiation of the complex social interactions among human agents, human beings have been endowed by evolution with intuitive mental tools necessary for social life.

For that reason, our agency detection device becomes hypersensitive: we detect agency based on limited evidence.  Particularly, in urgent situations of distress, where we cannot account for what is happening based on natural causes, we are quick to infer supernatural agents at work.  We then want to negotiate with these supernatural agents--spirits, ghosts, or gods--to protect ourselves from harm.  All human societies throughout history show this natural propensity to believe in supernatural agents to be a human universal.  The original expression of that religious experience was in our hunter-gatherer ancestors who had shamans as mediators with supernatural agents, and who lived in a world "haunted by spirits"--feeling the awe and dread of the Numinous, which Lewis saw as "the seed of the religious experience."

The subsequent development of religion beyond this original experience of awful spirits came through cultural evolution, in which some religious traditions had a selective advantage in that some were better than others in satisfying the innate mental tools of the evolved human mind for detecting supernatural agency.  Justin Barrett has argued that the Abrahamic monotheistic religions--Judaism, Christianity, and Islam--are more naturally attractive to the human mind, because the human mind is naturally inclined to believe in the divine traits of the Abrahamic God--God as moral, God as superknowing, God as immortal, God as superpowerful, and God as Creator.  This would confirm Lewis's claim that Judaism and Christianity became the most humanly satisfying forms of religious development.

But this Darwinian science of the biological and cultural evolution of religion as culminating in Abrahamic monotheism does not either prove or disprove the real supernatural existence of the Abrahamic God.  A Christian evolutionist like Justin Barrett can see this as showing that the natural evolution of religious belief is compatible with believing in the truth of Revelation, because we can believe that God used the evolutionary process to create a human mind that would have a desire for religious transcendence that would be fulfilled by faith in the revealed truth of God and Heaven.  But an atheistic evolutionist like Jesse Bering can see this natural evolution of religious belief as showing the natural human propensity for believing religious illusions.

Thus, Lewis's natural desire for Joy--for the Paradise of eternal life with God in Heaven--does not by itself prove the reality of that supernatural object of his desire.

We are left, then, with the unresolvable debate between Reason and Revelation, in which neither side can refute the other.  But as Lewis saw in his many years of debating atheists and skeptics in the Oxford Socratic Club, a modern liberal social order can secure the freedom of thought that makes it possible to have such a public debate that would not be possible in a more theocratic or illiberal social order.

And even if the Socratic and Darwinian zetetic philosophers lack the absolute knowledge or wisdom that would be necessary to refute Revelation, they can find such joy in the philosophic life of loving wisdom even without ever fully achieving it that they can attain the natural happiness possible in this life, so that they need feel no longing for a supernatural happiness in some heavenly afterlife.  Those living the philosophic life might even find joy in understanding--in at least some limited way--that everything in the Universe, and even the Universe itself, must eventually die.

I have written about the evolution of Heaven and Hell and given some reasons for agreeing with Wallace Stevens that "death is the mother of beauty."

Lewis was mistaken in thinking his desire for Joy was a desire for Heaven.  A deathless life in a heavenly paradise would not satisfy us, because it would not be a human life at all.

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.