Sunday, May 31, 2015

John Locke and the Modern Whig Revolution of 1688

In many posts, I have written about the two great revolutions in human history--the Neolithic Revolution, in which human beings moved from foraging to farming, and the Modern Revolution, in which human beings moved into commercial societies.  The Modern Revolution became most manifest in the first half of the 19th century with the Industrial Revolution in Great Britain and North America.  But the move towards the Industrial Revolution can be seen as early as the 17th century in Holland and England. 

John Locke saw this.  In his Two Treatises of Government, he suggested that human history broadly conceived could be divided into three eras--the foraging era, the farming era, and the commercial era.  As a radical Whig, Locke promoted the moral, economic, political, and philosophical ideas that would justify the Modern Revolution.  The most transformative turn in that direction during his life was the Glorious Revolution of 1688-89, in which James II was forced to abdicate the throne, and William and Mary took the throne.

To see the Glorious Revolution as part of the Modern Revolution is contrary, however, to the general view of many historians that the Revolution of 1688-89 was actually an un-revolutionary revolution, because it is seen as a bloodless and conservative revolution that restored the ancient constitution.  Thus, many historians have adopted Edmund Burke's argument (in Reflections on the French Revolution) that Richard Price was wrong to support the French Revolution of 1789 as following in the tradition of the Glorious Revolution, because that English revolution was a conservative restoration of English traditions, against the radical changes sought by King James II in his pursuit of absolute power.

And yet I have been persuaded by Steven Pincus (in 1688: The First Modern Revolution) that the Glorious Revolution really was a revolutionary transformation that prepared the way for the Industrial Revolution.  I have also been persuaded by Richard Ashcraft (in Revolutionary Politics & Locke's "Two Treatises of Government") that Locke saw this revolution as the fulfillment of his political thought and political activity as a radical Whig, and that the Two Treatises should be understood as the political manifesto of the radical Whig movement.

Locke's life as a radical Whig began in 1667, when he joined the household of Anthony Ashley Cooper, later the first Earl of Shaftesbury.  Locke became the tutor of Shaftesbury's son and grandchildren as well as Shaftesbury's personal physician, secretary, political advisor, close friend, and co-conspirator in plots for overthrowing Charles II.

Shaftesbury was one of the most prominent and controversial political leaders of the Restoration period.  Although he had fought with the Royalists in the Civil War until 1643, he joined the parliamentary side and became a member of Cromwell's Council of State.  After the Restoration in 1660, he came a strong defender of parliamentary authority and critic of royal absolutism.  He also supported the religious interests of the Dissenters and the argument for religious toleration.  And he was deeply involved in matters of trade, colonial expansion in North America, and in the advancement of the interests of merchants and traders.  As a Whig leader, he led an alliance with the lower classes of artisans and tradesmen to resist absolute power and to defend religious and political liberty.

What we today identify as Locke's liberalism was the liberalism that Locke learned from Shaftesbury.  The evidence for this is that while prior to 1667, Locke wrote essays defending royal absolutism and rejecting religious toleration, he reversed himself after 1667.

Locke shared Shaftesbury's fear that Charles II was plotting with French King Louis XIV to introduce a French Catholic absolutism to England.  In 1679-1681, they led the Whigs in agitating for the passing in Parliament of an Exclusion Bill that would exclude the brother of Charles--the Duke of York, the future James II--from succeeding to the throne.  The Whigs won three parliamentary elections, and the House of Commons passed an Exclusion Bill in 1680.  But Charles II frustrated their agenda by dissolving Parliament, and beginning in 1681, he refused to call Parliament into session for the rest of his reign.

Charles II set out to suppress his Whig opponents while supporting the Tories.  Most of the Whigs retreated and withdrew into inactivity.  But Shaftesbury led a small group of radical Whigs who were prepared for active revolutionary resistance to the King.  It was during this time that Locke began writing the Two Treatises as a theoretical defense of the radical Whig plan for violent revolution against Charles II.  The crucial doctrine for his argument was that in the state of nature, "every man hath a right to punish the offender, and be executioner of the law of nature," and when a ruler becomes an absolute tyrant, this dissolves the government, restores the state of nature, and thus restores the natural right of all men to defend themselves against those who threaten their lives, liberties, and properties (ST, 7-13).

Shaftesbury was arrested and charged with treason in 1681, but he was acquitted by the grand jury.  By the summer of 1682, Shaftesbury was actively planning a violent uprising.  In November of that year, fearing for his safety, Shaftesbury left England for Holland, where he died in January of 1683.

The plotting for overthrowing the King continued without Shaftesbury.  During this time, Locke was reading and taking notes on books about the history of political conspiracies, including Machiavelli's account of conspiracies in The Prince and the Discourses.  Locke was involved in the Rye House conspiracy, which was a plan to assassinate both Charles II and his brother James.  When the government learned about the Rye House conspiracy from informers, Locke left London in June of 1683, and went into hiding in the west of England.  In August, he left for Holland.  Throughout his time in Holland, he was in fear of being arrested and extradited to England to be tried for treason.  He moved in secret from one house to another in Holland.  An English envoy in Holland collected intelligence on the movements of Locke and the other radical Whig exiles in Holland.

Some of the Rye House conspirators were executed for treason, including Algernon Sydney, who had written his Discourses on Government as a defense of popular revolution for overthrowing tyrannical monarchs.  Sydney's arguments were similar to those in Locke's Two Treatises.

Locke had a studentship in Christ Church, Oxford University.  So he could have chosen to withdraw from political activity into a life of academic study at Oxford.  Instead, he chose to continue his participation in underground radical Whig plotting against the King.  As a consequence of this, he was expelled from his studentship at Oxford in 1684.

On February 6, 1685, Charles II died; and James II took the throne.  The radical Whigs planned a rebellion that would put the Duke of Monmouth, the son of Charles II, on the throne.  In July of 1685, Monmouth's Rebellion was defeated, and Monmouth was executed.

James II promoted a policy of religious toleration that would protect Catholicism in England.  Under the Penal Laws, anyone who did not participate in Anglican services could be fined and imprisoned.  Under the Test Acts, those who were not Anglicans could not serve in the military or in governmental offices.  In the Act of Indulgence of 1672, Charles II had used his prerogative power to suspend these laws.  James II wanted to continue this policy.  In 1687, James issued the Declaration of Indulgence that established a policy of toleration for Protestant Dissenters and for Catholics.  This created a dilemma for the proponents of religious liberty--Dissenters and radical Whigs.  On the one hand, they benefitted from the policy of toleration.  On the other hand, they rejected the King's claim that his royal prerogative included the power to dispense with the laws of Parliament.

Locke began writing his Letter Concerning Toleration in 1685, which resolved this dilemma by arguing that since "the care of each man's salvation belongs only to himself," religious belief is a matter of private conscience that is beyond any political authority (LCT, 13, 26).  Consequently, in demanding toleration, the Dissenters did not have to endorse the illegal power of the King to dispense with the laws, because they could see themselves as exercising their natural rights in rejecting any political authority over religious belief.  When any government denies religious liberty, it exercises force without right, which returns people to a state of nature, in which they may "resist force with force" in armed resistance to such oppression (LCT, 60).

With this kind of reasoning, Locke and other radical Whigs argued that in 1688, England had returned to a state of nature, because of James II's exercise of force without right, and thus the people were free to resume their natural right defend their life, liberty, and property, and to consent to the establishment of a new government.  But the moderate Whigs who joined the Tories in forcing James II to leave England and in crowning William and Mary did not agree with this radical Whig interpretation of the revolution.  When Locke returned to England in 1689, he took the side of the radical Whigs.

My point here in recounting this history is that Locke's philosophical writing was part of his active engagement in radical Whig political activity, including the Whig conspiracies for violent revolution.  So Locke's claim that all human beings have a natural executive power to defend themselves against aggressive attacks, including attacks on their rights from government, is not just a principle of abstract theorizing but a practical strategy of violent resistance to tyranny.  Locke himself chose to become an outlaw; and if he had been captured by Charles II or James II, he would have been beheaded, like Algernon Sidney and other radical Whig theorists. 

Moreover, this history also shows that Locke saw appeals to natural right as ultimately appeals to the force of arms, so that disagreements over right are settled by conspiratorial violence and military conflict.  Contrary to the common belief that the Glorious Revolution was a bloodless revolution, there were many violent clashes in the revolution; and the revolution would have failed if the military forces of James II had defeated the military forces of William III.

In a certain sense, therefore, Locke believed that "might makes right."  We can identify natural rights as those conditions for human life that cannot be denied without eventually provoking violent rebellion.  We might say that human rights are natural rights in so far as they are enforced by the natural human propensity to retaliate and take vengeance against, and feel revulsion towards, great injustices. 

This thought is developed here, here, here, and here.

To be continued . . .

Saturday, May 23, 2015

Locke's "Very Strange Doctrine" of the Natural Right to Punish

If Morris Hoffman is right that "evolution built us to punish," this could be the evolutionary basis for John Locke's argument that in the state of nature everyone has a natural right to punish offenses against the law of nature.  When people leave the state of nature by consenting to form a civil society, which establishes a government, everyone gives up that right to punish to the government.  But if that government exercises force without authority in using arbitrary, absolute power to threaten life, liberty, and property, then the people can rebel against the government in exercising force in self-defense, return to a state of nature, and reclaim their natural right to punish.

Locke originally wrote the Second Treatise of Government in 1681-1682 as a political declaration supporting the revolutionary conspiracy of the radical Whigs around Lord Shaftesbury, who were arguing that revolutionary violence was justified to defend the liberty of the people against the absolute monarchy of Charles II.  When the revolution failed, some of the radical Whigs were executed or imprisoned; and others, including Shaftesbury and Locke, were forced into exile in Holland.  Locke was in Holland from 1683 to 1689.  He was followed by spies and informers looking for the opportunity to have him arrested and extradited to England to be tried for treason.  After the Glorious Revolution of 1688, when James II was forced to leave England, and William of Orange sailed from Holland to England to take the throne with Mary, Locke revised the Second Treatise to include passages justifying the revolution by arguing that James II's claim of absolute power had thrown Great Britain into a state of nature, so that the people could exercise their natural right to resist tyranny and establish a new government.  The Second Treatise was published anonymously, and Locke never acknowledged his authorship during his lifetime.

Crucial for Locke's argument was his claim that when government becomes tyrannical, in using absolute power to threaten the lives, liberties, and property of the people, the government has been dissolved, because it violates the ends for which the people consented to the authority of the government; and if the government is dissolved, then everyone has the right to judge what is best for the public good and to engage in forceful resistance to achieve this end.

Locke recognized that it "will seem a very strange doctrine to some men" to teach that "every man hath a right to punish the offender, and be executioner of the law of nature" (ST, 8-9).  The men who think this a strange doctrine are the proponents of absolute monarchy, who cannot imagine how people could exercise such a power without creating utter confusion and disorder, because the judgment of people will be distorted by their self-love and their violent passions.  Locke conceded that government is the remedy for the violent conflict that arises in the state of nature, when people are judges in their own case.  But Locke observed that government by absolute monarchs is no remedy for these inconveniences in the state of nature, in which all are judges in their own case, because an absolute monarch is as much moved by self-love and turbulent passions as any other human being, and if he has the liberty to be judge in his own case and to execute his judgment with all the power of government, without anyone to question or control him,  this is much worse than the state of nature.  It is much better to be in a state of nature, where no one is bound to obey the unjust will of anyone else; and anyone who tries to take away the life, liberty, or property of others will provoke the retaliatory punishment that everyone can rightly inflict as executioners of the law of nature (ST, 13).

If we ask about the ground of that law of nature, Locke offers three answers: the natural equality of the human species, the equal dignity of human beings as God's workmanship, and the equality of human beings in their self-ownership.

First, Locke claims, we can see that the natural condition of human beings is a state of equality, "wherein all the power and jurisdiction is reciprocal, no one having more than another; there being nothing more evident, than that creatures of the same species and rank, promiscuously born to all the same advantages of nature, and the use of the same faculties, should also be equal one amongst another without subordination or subjection" (ST, 4).

Some readers of Locke have wondered whether this affirmation of the reality of the human species contradicts the apparent nominalism of Locke's argument in the Essay Concerning Human Understanding that we cannot know the real essence of species (III.6).  And yet, Locke affirms in the Essay that "there is nothing more obvious" than that nature makes animals of the same species "alike" (III.3.13).

If we accept evolutionary science, then we cannot believe that species are eternally fixed essences.  But still we can affirm the reality of biological species as enduring products of evolution.  Posts on this point can be found here, here, here, and here.

Still, we might wonder, how does our membership in the human species support the principles of natural law?  Locke's answer is that it supports the natural morality of the Golden Rule, or of Jesus' teaching that we should love our neighbors as ourselves.  Locke saw this a "a fundamental truth for the regulating human society" that could "determine all the cases and doubts in social morality" (Of the Conduct of the Understanding, 43). 

Locke explains his reasoning by quoting from Richard Hooker (ST, 5).  Since we are all of the same nature with similar desires, Hooker observes, I can understand that I cannot expect to have my desires satisfied by other people if I do not satisfy their desires.  "How should I look to have any part of my desire herein satisfied, unless myself be careful to satisfy the like desire, which is undoubtedly in other men, being of one and the same nature."  As I desire not to be harmed by others, they desire not to be harmed by me.  And if I do harm them, I can expect to suffer retaliatory harm from them.  If I desire to be loved by others, then I must also love them.  From this principle of reciprocity, natural reason can infer rules for the direction of life, such as these from Justinian's Code and Digest of Roman law: "What anyone approves in himself he cannot reprove in another."  "What anyone lays down as a law for another he ought also to abide by himself."  "One is entirely to abstain from all wrong and violence" (Of the Laws of Ecclesiastical Polity, I.8.7).

Locke has indicated in the First Treatise (86, 88) that natural desires create natural rights when human beings reflect on the conditions for satisfying their desires.  And so from understanding that all human beings by nature share my desire not to be harmed, I can infer that all human beings should have a natural right not to be harmed, and that when people initiate aggressive attacks on the life, liberty, or property of others, the injured parties have the right to punish them to achieve reparation of the damage they have suffered; and all others have the right to punish the offenders for the sake of restraining them and deterring others (FT, 10-11).  (We might see here the intimation in Locke that we derive "rights from wrongs," from our sense of injustice, as Alan Dershowitz argues.)

Thus, there are three levels of punishment.  By first-party punishment, those people with a conscience punish themselves by imagining the guilt they would feel if they unjustly harmed others (ST, 8, 122, 209).  By second-party punishment, the victims of aggression retaliate or seek vengeance against those who have injured them.  By third-party punishment, those who feel some concern for the victims punish the aggressors.

Morris Hoffman has shown how these three levels of punishment are expressed in the history of law as shaped by human evolutionary history, and how the evolution of the brain has shaped neural correlates for each of these three levels (Hoffman, The Punisher's Brain).  This has been the subject of a previous post.

Hoffman surveys much of the evidence and argumentation for the claim that our evolved social nature is complex.  We have evolved to cooperate, to cheat, and to punish cheaters.  We have evolved to cooperate because of the advantages of cooperative relationships.  But we have also evolved to cheat whenever that seems advantageous for us.  We have evolved to punish cheaters to restrain the propensity to cheating.  This would seem to support Locke's account in that we are naturally inclined to cooperate, but since many people are also naturally inclined to harm others, we are naturally inclined to punish those who harm us.

Evolutionary science and behavioral neuroscience also support Locke's claim that the natural law of cooperation can be understood as grounded on the Golden Rule.  Evidence from evolutionary theory and neuroscience suggests that there are complex genetic, neural, and hormonal mechanisms that have evolved for understanding and obeying the Golden Rule.  Neuroscientist Donald Pfaff has argued for this in two books--The Neuroscience of Fair Play: Why We (Usually) Follow the Golden Rule (2007) and The Altruistic Brain: How We Are Naturally Good (2015).  I have written about this kind of reasoning in various posts: here, here, and here.

But does this purely naturalistic ground for natural law and punishment--the evolved moral nature that we share with all members of the human species--contradict Locke's creationist account of natural law?  Locke often indicates that since all human beings were created in God's image, they are all his "workmanship" or property, and as such they are not to be attacked or destroyed, because this would deny their uniquely human dignity as God's special creation (FT, 30, 52-54, 85-86; ST, 6, 56; ECHU, IV.3.18).  This Lockean moral creationism is echoed in the famous language of the Declaration of Independence--that "all man have been created equal," and "endowed by their Creator with certain unalienable rights."

Some of the critics of Darwinian liberalism have argued that this shows that Lockean classical liberalism cannot be rooted in a purely natural Darwinian science without a creationist theology.  I have responded to these critics in posts here, here, here., here, and here,.

Darwin rejected the "special creation"--the idea that each living species, including human beings, had to be miraculously created by God.  But he acknowledged God as the Creator of the laws of nature, so that the Creator was the "primary cause" of everything, and the laws of nature were "secondary causes."  This kind of thinking allows many religious believers to be theistic evolutionists.

Darwin thought that "the conviction of the existence of an all-seeing Deity has had a potent influence on the advance of morality," and thus he could agree with Locke that belief in the Creator as the source of moral law could reinforce human morality (Descent of Man, 2004, 682).  But he thought the belief in a God who was omnipotent, moral, and caring for human beings arose only a few thousand years ago.  "The idea of a universal and beneficent Creator does not arise in the mind of man, until he has been elevated by long-continued culture."  He also thought that it was possible for many human beings to live by their conscience as "the supreme judge and monitor," without the necessity for believing in a God who rewards the good and punishes the bad.  We can be good without God.

So Darwin disagreed with Locke who declared--in his Letter on Toleration--that atheists could not be tolerated, because "promises, covenants, and oaths, which are the bonds of human society, can have no hold upon an atheist," and thus "the taking away of God, though but even in thought, dissolves all."

Evolutionary theorists who study the cultural evolution of religion--people like David Sloan Wilson, Ara Norenzayan, and Joseph Henrich--agree with Darwin.  They explain the appearance in the first agrarian states of prosocial religions with Big Gods or High Gods, Gods who are more powerful, more knowing, and more moralizing than the supernatural spirits of prehistoric religion.  They see this as favored by group selection in war: groups with prosocial religions were stronger than groups without such religions.  The beliefs and practices of these religions promoted social cooperation in large communities based on a shared belief in a morality enforced by an all-powerful and moralistic God.  Now the majority of human beings around the world are believers in one of the global prosocial religions--Hinduism, Buddhism, Judaism, Christianity, and Islam.  Economic game experiments with people around the world indicate that those who embrace one of these religions tend to have a stronger sense of fairness.  This could explain why Locke thought an appeal to Christian creationism could support a natural moral law of principles like the Golden Rule.

The third ground of Lockean natural law--the equality of human beings in self-ownership--can also be explained by an evolutionary account of human nature.  Everyone has property in his own person and in the extension of his person through labor, by which he appropriates things as property (ST, 27, 44, 163-64, 172).  Moreover, as a social animal dependent on parental care from birth, human beings extend their care for themselves to their sexual mates, their children, their parents, and other relatives.  These social instincts of mammalian psychology can then be extended beyond the family to others with ties of social affiliation.  Thus, human sociality is rooted in the biological inclinations for survival, mating, and reproduction (FT, 86-89; ST, 54-56, 77-84).

This Lockean conception of individual personhood as embodied self-conscious awareness of, and emotional concern for, the survival and well-being of the body can now be confirmed as manifest in the human nervous system as a product of mammalian evolution.  If we follow Antonio Damasio's "somatic marker hypothesis" and Bud Craig's neuroanatomical argument, we can identify the self-ownership of the person as an activity of the brain in constituting the subjective awareness of the individual in caring for one's self and for others to whom one is attached.

I have elaborated these points in posts here, here, and here.

Monday, May 18, 2015

The Evolution of Darwinian Liberalism

In December of 2013, I participated in a workshop on "Liberalism and the Evolutionary Agenda" in Freiburg, Germany.  I wrote a series of six posts on that workshop.

Now, the Journal of Bioeconomics (volume 17, number 1, 2015) has published some of the papers from that workshop, along with a paper by David Sloan Wilson.  Here is my article, which is a shortened version of the long paper that I presented at the workshop.

The evolution of Darwinian liberalism

Larry Arnhart


Abstract  From John Locke and Adam Smith to Herbert Spencer and Friedrich Hayek, the central idea of classical liberalism has been the thought that the social orders of morals, markets, laws, and politics can emerge as spontaneous orders—as largely self-regulating and unintended orders arising from the interaction of individuals pursuing their individual ends.  Darwinian evolutionary science supports this idea by showing how evolutionary order can arise from the evolution of self-ownership, property, and mammalian sociality and the evolution of exchange and the division of labor.  In developing these points, I argue for a Darwinian liberalism.


Keywords  Darwinism, Division of Labor, Evolutionary Psychology, Liberalism, Neuroscience, Property


The fundamental idea of classical liberalism is that society is largely a self-regulating, unintended order—a largely self-enforcing order created unintentionally by the free exchanges of individuals seeking to satisfy their individual desires (Barry 1982; Hamowy 1987; Raico 2012).  In this paper, I argue that Darwinian evolutionary science supports this fundamental idea of classical liberalism by sustaining an evolutionary liberalism as based on two evolutionary foundations--the evolution of self-ownership, property, and mammalian sociality and the evolution of exchange and the division of labor.  I thus add to the work of a few other scholars who have suggested ways in which an evolutionary science of human nature confirms liberal social thought (Rubin 2002; Turner and Maryanski 2008).


1  The evolution of self-ownership, property, and mammalian sociality


If classical liberalism is correct in assuming that society can arise as a largely self-regulating, unintended order from the actions of individuals seeking only the satisfaction of their individual desires, then the naturally self-seeking desires of individuals must lead them into social cooperation with others.  Adam Smith explains this as an expanding circle of human care rooted in care for oneself and then extended to care for one’s property, one’s family, and wider groups. Darwinian science supports this individualistic explanation of social order by showing how individuals are inclined by their evolved human nature as social mammals to care first for themselves, and then to extend that self-care into caring for property and for other individuals to whom they are attached.


1.1  Self-ownership as liberalism’s first principle of human nature


Classical liberalism teaches us that even if the cosmic order of the world does not care for or about us, we care for ourselves.  Consequently, the moral order of human social life conforms to the order of human care.  And having evolved to be the smart social mammals that we are, our human societies organize themselves through an expanding circle of human care.  Human beings naturally care first and foremost for themselves as individuals.  But as social animals who cannot live or thrive without the cooperative concern of others, human beings also care for and about others, and consequently they care for how they appear to others—seeking their approval and avoiding their disapproval.  Finally, through the power of our human imagination, we project our desire for social approval into a desire for the approval of an impartial spectator, which gives us a moral sense or conscience.

          Smith sketched that naturally expanding circle of human care.  Every person is first and primarily recommended to his own care, Smith observed, because every person is better situated to care for himself than for any other person, and because every person feels his own pleasures and pains more sensibly than those of others.  One’s feelings of one’s own pleasures and pains are the “original sensations,” and what one feels of the pleasures and pains of others is only “the reflected or sympathetic images of those sensations.”  After one’s care for oneself, one extends one’s affections first to one’s family—parents, children, siblings, and more distant relatives—then to one’s closer friends and neighbors, then to social relationships of gratitude and reciprocity, then to those individuals of high rank whom one admires, then to people whose suffering elicits one’s fellow-feeling, then to one’s country as stirring patriotic love, and finally, there can be some universal benevolence for all sensible beings insofar as they are brought to our attention (Smith 1982, pp. 219-35).

At the center of Smith’s expanding circle of care is one’s natural self-ownership, which is the first principle of liberalism.  Perhaps the earliest clear statement of this liberal principle was by Richard Overton in 1646.  Writing as one of the Levellers in the English Civil War, Overton began a political pamphlet by declaring: “To every individual in nature is given an individual property by nature not to be invaded or usurped by any.  For everyone, as he is himself, so he has a self-propriety, else could he not be himself.”  He saw this claim of self-ownership as an instinctive natural desire.  And insofar as every individual can recognize that every other individual naturally asserts the same claim to self-ownership, everyone can see that he must respect the natural liberty of others if he expects them to respect his natural liberty.  For if he infringes on the natural liberty of others, he will provoke their resentment and retaliation (Overton 1998, pp. 55-57).

          Later, Locke adopted this same principle of self-ownership as the ground of natural rights (Zuckert 2002, pp. 3-7, 193-97, 324-26).  In his Second Treatise of Government, Locke asserts: “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 has provided, and left it in, he hath mixed his Labour with, and joined to it something that is his own, and thereby makes it his Property” (par. 27).  Locke thought it self-evident that though the resources of nature are available in common for all, each man as master of himself and proprietor of his own person could extend himself through labor to claim property in those natural resources (par. 44).

Later, in the nineteenth century, British liberals like Auberon Herbert (1978) elaborated this principle that each person as “self-owner” was the “owner of his own mind and body and his own property” (pp. 369-75).  Today, classical liberals like Charles Murray (1997) continue to appeal to this principle of self-ownership.

          Locke’s understanding of self-ownership was founded in a biological conception of embodied self-awareness.  Locke was a medical doctor and a biomedical researcher who worked closely with some of the leading medical scientists of his day, such as Thomas Sydenham, Robert Boyle, and Thomas Willis (Dewhurst 1963; Woolhouse 2007).  For example, he contributed to Boyle's experiments with his air-pump to explore how air provided some element necessary for respiration, which apparently sustained the natural heat of the heart that was necessary for life.  Thus, Boyle and Locke were close to the discovery of oxygen's role in sustaining animal life.  One of Locke's earliest writings was a draft manuscript on the importance of air in respiration.  He wrote: "Nature's aim seems to have been to foster that universal heat or fire of our life. For we live as long as we burn, and are nourished by the same fire” (Woolhouse 2007, p. 68).   Here he saw the natural teleology of functional processes in biology.

Locke also learned about how the human mind emerges from the brain and nervous system from Willis, who was the founder of modern neurology (Zimmer 2004).  Like Aristotle, Willis dissected monkeys and apes to study their neurological similarities to human beings, while also looking for differences that would explain the distinctiveness of the human mind.

In his Essay Concerning Human Understanding, Locke identified a "person" or "self" as "a thinking intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing, in different times and places."  All the parts of a human body are vitally united to this thinking self, "so that we feel when they are touched, and are affected by, and conscious of good or harm that happens to them, are a part of ourselves; i.e. of our thinking conscious self."  So that "the limbs of his body are to every one a part of himself; he sympathizes and is concerned for them."  "Self is that conscious thinking thing . . . which is sensible or conscious of pleasure and pain, capable of happiness or misery, and so is concerned for itself, as far as that consciousness extends.  Thus every one finds that, whilst comprehended under that consciousness, the little finger is as much a part of himself as what is most so” (1959, II.xxvii.9, 11, 17).

This Lockean conception of individual personhood as embodied self-conscious awareness of, and emotional concern for, the survival and well-being of the body can now be understood as rooted in the mammalian evolution of the human nervous system.

1.2  The neurobiology of care

The biological psychology of human care can be illuminated through Antonio Damasio’s  (1994) "somatic marker hypothesis" for explaining the importance of emotion in decision-making and consciousness.  Building on an idea proposed by William James and Carl Lange, Damasio believes that emotions arise from physiological states of the body, so that, for example, the emotion of fear arises from the physiological disturbance of the body associated with some fearful event.  Emotions help us to make decisions by assigning emotional valence to our choices. Through imaginative projection, we can foresee the emotional outcome of a choice by anticipating how we will feel--our somatic markers--if we make that choice, and thus we might avoid a choice with fearful associations.  Ultimately, this emotional decision-making mechanism is an evolutionary adaptation to secure the survival and well-being of the body.

This line of thought has been extended by A. D. (Bud) Craig, a functional neuroanatomist.  He has traced out the fundamental neuroanatomical basis for all human emotions, and he has argued that this shows how the neural substrates for human self-awareness or consciousness are based on the neural representation of the physiological state (the homeostasis) of one's body.  This manifests the embodiment of emotional self-consciousness.  In particular, he argues that there is a phylogenetically novel sensory pathway in primates, most fully developed in human beings, that provides for a self-conscious integration of the physiological condition of the body (the material "self") with one's sensory environment, with one's motivational condition, and with one's social situation in the anterior insular cortex (AIC) (Craig 2002, 2003, 2008).

In imaging studies of emotion, the AIC is jointly activated with the anterior cingulate cortex (ACC).  The AIC seems to be the primary site for generating self-awareness from representations of the feelings from the body, while the ACC seems to be the site for the initiation of behavior, which thus provides volitional agency.

This could be the evolutionary neurophysiological basis for Locke's account of natural rights.  Reasoning about natural rights ultimately depends on discerning natural human inclinations, such as self-preservation, property, social attachment, practical judgment, and intellectual understanding, which correspond to what I have identified as the twenty natural desires.  Evolutionary neuroscience explains how the human nervous system has evolved to serve those natural inclinations or desires.  The concrete expression of those natural inclinations varies according to individual temperament, individual life history, and cultural circumstances.  But there is a universal human pattern that manifests the evolved natural needs of human beings as the smart social mammals that they are.

The evolution of mammalian social behavior depends on the evolution of pain or "negative affect," which includes pain, fear, panic, and anxiety.  In all vertebrates, fear and pain are represented in the brainstem and hypothalamus as signals to elicit self-preserving behavior.  In mammalian evolution, these neural mechanisms are modified so that animals care for their offspring as well as themselves.  This includes modifying the cortex of the mammalian brain to elaborate the representation of pain to include anxiety tied to separation from or threat to loved ones.

Craig's research clarifies this neural evolution of pain by classifying pain as a homeostatic emotion rather than as a sensation of touch.  Pain belongs to "interoception"--the sense of the physiological condition of the body--and it is therefore part of the evolved mechanisms for self-preservation.  The insular cortex receives signals from all the tissues of the body, and these signals are integrated with physical and social stimuli from outside the body and with the memory of past experiences as well as imaginative projections of future experiences.  This supports a general awareness of the body's condition in space and time.  The ACC can then be activated to motivate behavior to correct whatever is wrong.  This neural processing mechanism seems to be unique to primates, but it's more highly developed in human beings.

Both the insular cortex and the ACC respond not only to physical pain from bodily injury but also social pain from social injury.  In mammalian evolution, the neural circuitry for physical pain was appropriated for registering social pain in animals adapted for social attachment.  Mammals have evolved to care for the survival and well-being not only of themselves, but also of others to whom they are attached.  Extending the neural mechanisms originally evolved for individual self-preservation to include the welfare of offspring and social partners secures mammalian social order.  The uniquely human evolution of the neocortex elaborates this mammalian development to sustain human love and concern for others.  When we use the language of physical pain to metaphorically describe our social pain, as when we speak of suffering "a broken heart,” we suggest the embodiment of our natural social consciousness, in which our mind, our brain, our body, and our social life are inseparably intertwined.  After all, being rejected by others really does hurt us, and we can see how this is rooted in our evolved nervous system (Eisenberger and Lieberman 2004).

Social neuroscience is beginning to explain the neurochemistry of mammalian attachment as the natural ground for human morality and social order as rooted in human care (Zahn, Oliveira-Souza, and Moll 2011; Churchland 2011, 2013).  As shaped by evolutionary history, nervous systems are organized to take care of the body.  Animals with neural adaptations inclined to care for themselves and for their well-being are selected over those that neglect their self-preservation.   In mammals, this caring for oneself is extended into care for others--for one's offspring, for one's mate, for one's kin, and for others in one's group.  We are now beginning to explain how this works through the neurochemistry of factors such as oxytocin and vasopressin, which support attachment and bonding.  This sustains the basic social desires or sentiments that lead to human morality.   This neurobiology of mammalian sociality confirms the argument of Locke, Smith, and other liberal thinkers about the importance of mammalian biology as the natural ground for the unintended social order of family life (Locke 1988, I.86-88, II.77-79; Smith 1982b, pp. 141-43, 438).

Because of our evolved human nature, we care not only for ourselves and other persons to whom we are attached, but also for the physical goods that have some value for us, and thus we have a natural desire for property.


1.3  The biology of property

A Darwinian view of human nature sustains the liberal commitment to private property as a natural propensity that is diversely expressed in custom and law.  The particular rules for property rights are determined by customary traditions and formal laws that vary across history and across societies, but that variation is constrained by the natural desire for property.  We need to understand the complexity of property across three levels--natural property, customary property, and formal property (Arnhart 2009, pp. 59-67).

This is illustrated in the historical case of mining law in California.  Once gold was discovered in northern California in 1848, hundreds of thousands of people went there to search for gold, and they showed their natural instinct for property by claiming land for mining by taking possession of it, although they were only squatters on land officially owned by the federal government of the United States.  To settle disputes over mining claims, the miners developed customary rules that they enforced among themselves by social tradition.  Then, finally, in 1866, the United States Congress passed a federal mining law that formally legalized these local customs of the miners.

Thus, the property claims of the miners moved through three levels--natural possession, customary rules, and formal laws.  This manifests the general structure of Darwinian social order as the joint product of natural desires, cultural practices, and deliberate judgments.

In recent years, a growing number of law professors have become interested in the evolutionary analysis of law, and one prime area of research has been the evolutionary analysis of property law.  This research confirms the Darwinian account of property (Krier 2009; Stake 2004; DeScioli and Wilson 2011).

This research provides a scientific confirmation for the evolutionary explanation of property laid out originally by Locke (in his Two Treatises of Government), William Blackstone (in his Commentaries on the Laws of England), and Adam Smith (in his Lectures on Jurisprudence) (Smith 1982b, pp. 13-39).   First, among ancient foraging bands, hunting territory was owned communally by the band--excluding other bands--and personal property (such as weapons, tools, and clothing) was owned individually.  These original claims to property were based on possession and occupancy, so that the first person or group to take and hold possession of some scarce resource was presumed to own it.  This was enforced by customary agreement.  But, then, when agriculture was developed, the growing scarcity and demand for land made it necessary to settle property disputes through the formal institutions of government, and the invention of writing facilitated this.  Finally, with the expansion of commerce and trade, property rights became ever more subject to rules of sale, grant, or conveyance.

We might explain part of the evolutionary logic for property through John Maynard Smith's (1982) evolutionary game theory analysis of how the "bourgeois" strategy develops among animals to settle disputes over territory and resources.  If we imagine two animals competing for access to a particular breeding territory, and if they have an equal opportunity of arriving first and possessing it or arriving later and being an intruder, we might imagine two possible strategies: the Hawk who fights until one animal is injured and retreats, and the Dove who bluffs but never fights. Under certain conditions, the best strategy is a "bourgeois" strategy that mixes the other two: "if owner, play Hawk; if intruder, play Dove."  In fact, many animals do seem to play this strategy, so that the possessor of a territory tends to have an advantage over an intruder, and consequently there is a kind of instinctive rule of property that favors possessors over intruders, because possessors will risk injury to defend their possessions, while intruders will retreat in response to the threat of injury.  Of course, explaining territorial behavior among animals requires weighing many factors that influence the costs and benefits of defending territory, which goes beyond a simple choice between two strategies (Alcock 2013, pp. 142-52).  But the general point is that it is adaptive for animals to defend their possession of appropriated resources.

The primacy of possession runs through much of our property law, and this could be because it is rooted in the evolved structure of our brains so that it feels right to us.  One lawyer concludes: "Possession, as any property lawyer knows, remains the cornerstone of most contemporary property systems--nine points of the law, the root of title, and the origin of property” (Krier 2009, p. 159).  Included in the right of possessing property is the right of exchanging one’s property for the property of others, which allows for the mutual gains from trade (Westermarck 1906, vol. 2, pp. 1-71).

2  The evolution of exchange and specialization


The liberal idea of society as a largely self-sustaining order assumes that this arises as an unintended outcome of the actions of individuals naturally inclined to mutual exchange and a division of labor.  Smith explained this in The Wealth of Nations as rooted in the human “propensity to truck, barter, and exchange.”  Darwinian science confirms this liberal idea by showing how a natural propensity to exchange and specialization arose in human evolution, and how the modern cultural evolution of exchange and specialization explains the explosive growth in the prosperity, population, and liberty of the modern world. 

2.1  The evolution of the “propensity to truck, barter, and exchange”


Smith claims in The Wealth of Nations that the "propensity to truck, barter, and exchange one thing for another" is uniquely human and not found in any other animals (1981, p. 25).  Is this true, and, if true, what would it mean for our understanding of human social life?

Haim Ofek (2001) and Matt Ridley (2010) have argued that what we now know about human evolution confirms Smith's insight about the unique importance of exchange for human history.  The whole of human history for the past 200,000 years can be understood as the progressive extension of human cooperation through exchange and the division of labor--from foraging bands to agrarian states to modern commercial societies in global networks of trade.  Both Ofek and Ridley see this as arising from a human propensity to exchange that cannot be seen in any other animal.

In the first chapter of The Wealth of Nations, Smith explains the division of labor as the primary cause for the increasing productivity, which includes the famous example of the pin factory.  In the second chapter, he explains how this division of labor arose in human history:  "This division of labour, from which so many advantages are derived, is not originally the effect of any human wisdom, which foresees and intends that general opulence to which it gives occasion.  It is the necessary, though very slow and gradual consequence of a certain propensity in human nature which has in view no such extensive utility; the propensity to truck, barter, and exchange one thing for another” (p. 25).   Smith does not see this propensity in other animals: “Nobody ever saw one animal by its gestures and natural cries signify to another, this is mine, that yours; I am willing to give this for that” (p. 26).   Animals beg for help, and human beings also do this as well.  But in a large civilized society, human beings require the cooperation of a great number of strangers who feel no love, friendship, or benevolence for them.  Consequently, in such a large human society, we must secure the cooperation of strangers through mutually beneficial trading:  “Give me that which I want, and you shall have this which you want, is the meaning of every such offer; and it is in this manner that we obtain from one another the far greater part of those offices which we stand in need of.  It is not from the benevolence of the butcher, the brewer, or the baker, that we expect our dinner, but from their regard to their own interest” (pp. 26-27).

Smith then indicates that the emergence of a division of labor through exchange appears originally among savages living as hunter-gatherers, where someone might specialize in making bows and arrows that he can trade for some meat captured by a hunter, so that each fills a particular occupation, and thus their joint labor becomes more productive than would be the case if each were working only for himself (1981, pp. 27-28; 1982b, pp. 347-49).  This is part of Smith's understanding of human social evolution as passing through four stages of social life--from foraging to herding to farming to commerce.  Smith and other Scottish philosophers developed a theory of the four stages in social evolution from their study of the reports about the native Americans in the New World.  This was the beginning of evolutionary anthropology (Meek 2011).

At the beginning of The Wealth of Nations, we see the fundamental idea that is common to Smith's social thought and Darwin's biology--the possibility of design-without-a-designer ("not originally the effect of any human wisdom") through emergent or spontaneous order.   Smith then poses an evolutionary question: Was the propensity to exchange an original principle of human evolution, or was it a late by-product of earlier evolved "faculties of reason and speech"?  Although he chooses not to take up this question here, he considers it more probable that reason and speech came first, and then the propensity to exchange came later as a by-product.  In the Lectures on Jurisprudence, Smith says that the "real foundation" of exchange and the division of labor is "that principle to persuade which so much prevails in human nature” (1982b, p. 352).   Like Aristotle, Smith believes that human beings are more political than other political animals because human beings have a capacity for logos--reason or speech--that allows them to persuade one another to cooperate for common ends, which makes exchange and the division of labor possible.  Ofek argues, however, that the evidence of human evolutionary history now suggests that exchange was an early agent of human evolution that favored the evolution of human reason and speech.

Smith goes on to suggest that while other animals can seem to act in concert when they are in passionate pursuit of the same object--like greyhounds chasing the same hare--this is the consequence not of any contract or deliberate choice but of "the accidental concurrence of their passions" in pursuing the same object at the same time.  Non-human animals are unable to communicate with one another well enough to say: "this is mine, that yours; I am willing to give this for that."

Smith does think that non-human animals can engage in persuasion by begging for attention within their families or their groups or even to elicit benevolent care from human beings.  But the range of benevolence for all animals--including human beings--is limited.  In human civilization, individuals need "the cooperation and assistance of great multitudes," and for this they must appeal not to benevolence but to self-love, by persuading other individuals to engage with them in mutually beneficial exchanges.  Indeed, Smith points out that among human beings, even beggars cannot rely totally on charitable benevolence to secure their needs, because they beg for money that they use to buy what they need.

We might wonder whether Darwin would agree with Smith about barter or exchange being unique to human beings in giving rise to the division of labor as a spontaneous order.  Remarkably, Darwin says little about exchange in human evolution.  But there are at least two passages in Darwin's writings that both Ofek and Ridley cite as supporting their arguments about the human evolution of exchange.

In the Voyage of the Beagle, Darwin described the savage people that he saw at Tierra del Fuego, at the far southern tip of South America.  He thought the Fuegians showed the most primitive level of human social life.  "Some of the Fuegians plainly showed that they had a fair notion of barter. I gave one man a large nail (a most valuable present) without making any signs for a return; but he immediately picked out two fish, and handed them up on the point of his spear. If any present was designed for one canoe, and it fell near another, it was invariably given to the right owner” (2004a, p. 201).  Darwin seems, then, to agree with Smith that even those living in the most primitive foraging societies show "the propensity to truck, barter, and exchange one thing for another."

In The Descent of Man, Darwin described how man became "the most dominant animal" through technological inventions such as tools:

To chip a flint into the rudest tool, or to form a barbed spear or hook from a bone, demands the use of a perfect hand; for, as a most capable judge, Mr. Schoolcraft, remarks, the shaping fragments of stones into knives, lances, or arrow-heads, shews 'extraordinary ability and long practice.' This is to a great extent proved by the fact that primeval men practised a division of labour; each man did not manufacture his own flint tools or rude pottery, but certain individuals appear to have devoted themselves to such work, no doubt receiving in exchange the produce of the chase (Darwin 2004b, p. 69).

Darwin implies that the complexity of artifacts in the archaeological record could be interpreted as evidence for a division of labor that promotes the dexterity and inventiveness that comes from specialization.  Ofek and Ridley have adopted this line of reasoning in arguing that the explosion of technological complexity in the Upper Paleolithic record of human evolution is a consequence of exchange and specialization, which is confirmed by evidence that some of the material in the human artifacts was transported over long distances, apparently through trade.

Darwin does not indicate, however, that this propensity for exchange and a division of labor is uniquely human, as Smith does.  Ridley argues that recent research on the evolution of cooperation confirms Smith's view.  Other animals cooperate with one another based on kinship, relatedness, and reciprocity (direct and indirect), and human cooperation shows these same evolved mechanisms at work.  But cooperation based on exchange or barter is uniquely human, and it cannot be explained as a form of reciprocity.  Reciprocity means giving each other the same thing.  I'll scratch your back if you scratch mine (direct reciprocity).  Or I'll scratch your back because you have a reputation for scratching the backs of others (indirect reciprocity).  But exchange means giving each other different things.  As Smith puts it, "Give me that which I want, and you shall have this which you want."  Other animals can't do this.

To support this conclusion, Ridley cites some experiments with chimpanzees:

The primatologist Sarah Brosnan tried to teach two different groups of chimpanzees about barter and found it very problematic. Her chimps preferred grapes to apples to cucumbers to carrots (which they liked least of all). They were prepared sometimes to give up carrots for grapes, but they almost never bartered apples for grapes (or vice versa), however advantageous the bargain. They could not see the point of giving up food they liked for food they liked even more. Chimpanzees and monkeys can be taught to exchange tokens for food, but this is a long way from spontaneously exchanging one thing for another: the tokens have no value to the chimpanzees, so they are happy to give them up. True barter requires that you give up something you value in exchange for something else you value slightly more (Ridley 2010, p. 59).

Here Ridley is obscuring some of the complexity in these experiments (see Brosnan 2008).  Brosnan and her colleagues apparently showed that chimps do barter, at least in a situation where they can trade very low valued items (carrots) for very high valued items (grapes).  But they do not barter where the gains from barter are small--as in trading valuable apples for slightly more valuable grapes.  One possible explanation that they suggest is that the chimps are less inclined to take the risk from giving up a valued food item if the possible gains are too small.

Nevertheless, these experiments do provide some support for the Smith/Ridley position.  Even if these chimps can learn to barter under some special conditions in the laboratory, they don't seem to spontaneously barter in the wild.  This is in contrast to the human situation where bartering comes easily as a spontaneous behavior, even in the most primitive human conditions, as with Darwin's Fuegians.

2.2  The neurobiology of exchange


If exchange has been an important factor for human evolution for a hundred thousand years or more, then we can expect that human neurobiological systems support the disposition to exchange.   Paul Zak (2012) has performed some game-theory experiments that seem to show that this disposition to exchange as based on trust is supported by the neuroactive hormone oxytocin, which is found in all mammals, and which evolved originally to support maternal care of offspring.   The ancient evolution of oxytocin in human beings and other mammals suggests deep evolutionary roots for extended human cooperation.

Zak argues that economic exchange depends upon moral values, because it depends upon the trust that makes cooperation possible.  There is evidence that this disposition to trust and cooperation has evolved to be part of human nature, although the expression of that disposition varies in response to the cultural environment.  We are now beginning to explain the neural mechanisms of this evolved moral nature.  In particular, Zak has shown experimentally that oxytocin supports moral cooperation by promoting attachment to offspring, to reproductive partners, to friends, and even to strangers.  What originally evolved to promote mammalian maternal care for offspring has been extended to embrace ever wider groups of individuals who benefit from exchange.

Zak sees economic exchange as rooted in evolved human nature:

Values are not specific to the West or East, nor are there broadly distinct Western and Eastern economic institutions.  Rather, values across all cultures are simply variations on a theme that is deeply human, strongly represented physiologically, and evolutionarily old. Similarly, the kinds of market institutions that create wealth and enable happiness and freedom of choice are those that resonate with the social nature of human beings who have an innate sense of shared values of right, wrong, and fair.  Modern economies cannot operate without these (Zak 2008, p. 276).

Zak agrees with Friedrich Hayek (1991) in seeing the modern transition from personal exchange to mostly impersonal exchange in markets as making possible the great increases in wealth and population since the Industrial Revolution.  But in contrast to Hayek, Zak sees this cultural tradition of impersonal exchange as developing an innate potentiality of evolved human nature.

One can see this in the research of Joseph Henrich and his colleagues (2010) who studied the play of the Ultimatum Game in small-scale societies around the world. Variations in the play of the game manifested variations in the cultural norms of the societies.  The higher rates of fair offers in the game were associated with those societies that had high levels of market activity.  It seemed that people who regularly engaged in trade learned that successful trading required that traders agree on a fair distribution of gains.  The genetically evolved neural mechanism of oxytocin as favoring trust will fluctuate in response to the culturally evolved social environment.  Thus, a Darwinian explanation of exchange behavior requires a coevolutionary explanation of the interaction between genetic evolution and cultural evolution, in which cultural evolution taps into human genetically evolved psychology.


3  Conclusion

In one of the first reviews of Darwin’s Origin of Species, Thomas Henry Huxley (1860) declared that “every philosophical thinker hails it as a veritable Whitworth gun in the armory of liberalism.”  The Whitworth gun was a new kind of breech-loading cannon.

          If the fundamental idea of liberalism is that social order can arise as a largely self-regulating and unintended order from the free exchanges of individuals seeking to satisfy their individual desires, then Darwinian evolutionary science truly is a powerful weapon for liberalism insofar as it supports that idea.  It does that by showing how an evolutionary liberalism can be grounded on the evolution of self-ownership, property, and mammalian sociality and on the evolution of exchange and the division of labor.



Alcock, J. (2013). Animal behavior. 10th ed. Sunderland, MA: Sinauer Associates.

Arnhart, L. (2009). Darwinian conservatism. Exeter, UK: Imprint Academic.

Barry, N. (1982). The tradition of spontaneous order. Literature of Liberty 5, 7-58.

Brosnan, S., Grady, M. F., Lambeth, S. P., Schapiro, S. J., & Beran, M. J. (2008). Chimpanzee autarky. PLoS ONE, 3, e1518, 1-5.

Churchland, P. (2011). Braintrust: What neuroscience tells us about morality. Princeton, NJ: Princeton University Press.

Churchland, P. (2013). Touching a nerve: The self as brain. New York: W. W. Norton.

Craig, A. D. (2002). How do you feel? Interoception: The sense of the physiological condition of the body. Nature Reviews Neuroscience, 3, 655-666.

Craig, A. D. (2003). A new view of pain as a homeostatic emotion. Trends in Neuroscience, 26, 303-307.

Craig, A. D. (2008). Interoception and emotion: A neuroanatomical perspective. In M. Lewis, J. Haviland-Jones, and L. Barrett (Eds.), Handbook of Emotions, 3rd ed. New York: Guilford (pp. 272-88).

Craig, A. D. (2009). How do you feel—now? The anterior insula and human awareness. Nature Reviews Neuroscience, 10, 59-70.

Damasio, A. (1994). Descartes’ error: Emotion, reason, and the human brain. New York: G. P. Putnam’s Sons.

Darwin, C. (2004a). The descent of man, and selection in relation to sex. New York: Penguin.

Darwin, C. (2004b). The voyage of the beagle. Washington, DC: National Geographic Society.

DeScioli, P., & Wilson, B. (2011). The territorial foundations of human property. Evolution and Human Behavior, 32, 297-304.

Dewhurst, K. (1963). John Locke (1632-1704), physician and philosopher: A medical biography. London: Wellcome Historical Medical Library.

Eisenberger, N. I., & Lieberman, M. D. (2004). Why rejection hurts: A common neural alarm system for physical and social pain. Trends in Cognitive Sciences 8, 294-300.

Hamowy, R. (1987). The Scottish enlightenment and the theory of spontaneous order. Carbondale: Southern Illinois University Press.

Hayek, F. (1991). The fatal conceit: The errors of socialism. Chicago: University of Chicago Press.

Henrich, J., Ensminger, J., McElreath, R., Barr, A., Barrett, C., Bolyanatz, A., Cardenas, J. C., Gurven, M., Gwako, E., Henrich, N., Lesorogol, C., Marlowe, F., Tracer, D., & Ziker, J. (2010). Markets, religion, community size, and the evolution of fairness and punishment. Science 327, 1480-1484.

Herbert, A. (1978). The right and wrong of compulsion by the state, and other essays. Indianapolis, IN: Liberty Fund.

Huxley, T. H. (1859). The origin of species. Westminster Review 17, 541-70.

Krier, J. E. (2009). Evolutionary theory and the origin of property rights. Cornell Law Review 95, 139-60.

Locke, J. (1959). An essay concerning human understanding. 2 vols. New York: Dover Publications.

Locke, J. (1988). Two treatises of government. Cambridge: Cambridge University Press.

Maynard Smith, J. (1982). Evolution and the theory of games. Cambridge: Cambridge University Press.

Meek, R. L. (2011). Social science and the ignoble savage. Cambridge; Cambridge University Press.

Murray, C. (1997). What it means to be a libertarian: A personal interpretation. New York: Broadway Books.

Ofek, H. (2001). Second nature: Economic origins of human evolution. Cambridge: Cambridge University Press.

Overton, R. (1998). An arrow against all tyrants. In A. Sharp (Ed.), The English levellers (pp. 54-72). Cambridge: Cambridge University Press.

Raico, R. (2012). Classical Liberalism and the Austrian School. Auburn, AL: Ludwig von Mises Institute.

Ridley, M. (2010). The rational optimist: How prosperity evolves. New York: HarperCollins.

Rubin, P. H. (2002). Darwinian politics: The evolutionary origin of freedom. New Brunswick, NJ: Rutgers University Press.

Smith, A. (1981). An inquiry into the nature and causes of the wealth of nations. Indianapolis: Liberty Fund.

Smith, A. (1982a). The theory of moral sentiments. Indianapolis: Liberty Fund.

Smith, A. (1982b). Lectures on jurisprudence. Indianapolis: Liberty Fund.

Stake, J. E. (2004). The property instinct. Philosophical Transactios of the Royal Society of London B, 359, 1763-1774.

Turner, J. H., & Maryanski, A. On the origin of societies by natural selection. (2008). Boulder, CO: Paradigm Publishers.

Westermarck, E. (1906). The origin and development of the moral ideas. 2 vols. London: Macmillan.

Woolhouse, R. (2007). Locke: A biography. Cambridge: Cambridge University Press.

Zahn, R., de Oliveira-Souza, R, & Moll, J. (2011). The neuroscience of moral cognition and emotion. In J. Decety & J. T. Cacioppo (Eds.), The Oxford handbook of social neuroscience (pp. 477-90). New York: Oxford University Press.

Zak, P. (2008). Values and value: Moral economics. In P. Zak (Ed.), Moral Markets: The Critical Role of Values in the Economy (pp. 259-79).  Princeton, NJ: Princeton University Press.

Zak, P. (2012). The moral molecule: The source of love and prosperity. New York: Dutton.

Zimmer, C. (2004). Soul made flesh: The discovery of the brain—and how it changed the world. New York: Free Press, 2004.

Zuckert, M. P. (2002). Launching liberalism: On Lockean political philosophy. Lawrence: University Press of Kansas.