In many of my posts and published writings over the years, I have argued that my reasoning for "Darwinian natural right" could support much of Thomas Aquinas's reasoning for natural law and John Locke's reasoning for natural rights. If I am right about this, then the ideas of "natural right," "natural law," and "natural rights" should all be ultimately explicable as rooted in the evolutionary neuroscience of human social order. If we can explain human sociality as the outcome of mammalian evolution, then there should be mechanisms in the human nervous system to support the moral psychology of human social life. Advances in human social neuroscience should therefore explain the neural basis for the human social nature studied by political philosophers.
Consider, for example, Locke's argument for natural rights as rooted in divine ownership and self-ownership.
In the Second Treatise, Locke grounds 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 anothers 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 anothers uses, as the inferior ranks of Creatures are for ours. (sec. 6)
Those scholarly interpreters--like James Tully and Brian Tierney--who see Locke as a natural law theorist in the tradition of Aquinas and Richard Hooker emphasize this Lockean declaration of creationist theology, in which "natural rights" can be understood as permissions within the order of natural law as established by God.
But those--like Leo Strauss and Michael Zuckert--who see Locke as a modern natural rights theorist in the tradition of Hobbes emphasize Locke's affirmation of of individual self-ownership in his chapter on property.
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. (sec. 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. (sec. 44)
Here, Zuckert argues, 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, Zuckert insists, it is this natural autonomy of human beings, rather than their natural subordination to God, that informs the modern understanding of human rights.
Here we see a tension or contradiction that runs through much of our modern debate about liberal political thought. On the one hand, some people argue that human rights depend upon religious belief in creationism--in the the idea that human beings have been created by God and endowed by Him with rights (as asserted by the Declaration of Independence). On the other hand, other people argue that human rights depend on a purely secular belief in individual autonomy, which includes the freedom of individuals from any politically enforced establishment of religion. So how we interpret Locke has implications for this continuing debate in liberal societies over the relationship between religious belief and liberal politics.
Recently, Adam Seagrave--one of Zuckert's students--has offered an interpretation of Locke that resolves this tension, so that Locke's arguments for divine ownership and self-ownership can be compatible. The key is in seeing how divine ownership and self-ownership apply to two different but concurrent facets of human beings.
On the one hand, God has created the generic traits of human beings as belonging to the same human species--"being furnished with like Faculties, sharing all in one Community of Nature"--as distinguished in their uniquely human nature from other animals--"the inferior ranks of Creatures."
On the other hand, human beings as distinguished from one another have each a "person" or "self" that arises as the product of each individual's self-conscious workmanship.
It seems that in creating human beings in His own image as a creative mind, God created them with the capacity for self-conscious creating. Thus, God created human beings as potential self-creators and thus self-owners. Human beings are created co-creators. (TT.I.30, 39; II.44). Consequently, "in respect of God the Maker of Heaven and Earth," human beings are God's property; but "in respect of one another," they have property in themselves and in whatever they appropriate to themselves (TT.I.39).
Seagrave thinks this opens up a Lockean resolution to the contuing debate over the relationship between religion and politics in liberal regimes. He writes:
The premise of self-ownership is not derived from, and may be conceived entirely independent of, the premise of Divine ownership. Similarly, the premise of Divine ownership may be conceived independently from the premise of self-ownership. The two premises considered together, however, are compatible and even in profound harmony with one another. . . . This framework opens up a true common ground, rather than a mere overlap, between atheist and religious citizens of liberal democracies in the idea of self-ownership despite persistent disagreement regarding the premise of Divine ownership. This common ground is also potentially open to citizens subscribing to very different religious doctrines; despite the persistence of heated religious controversy, both premises that enter into the "nesting" property framework may be accepted by such citizens.
I wonder, however, how Seagrave would explain Locke's argument--in the "Letter Concerning Toleration"--that atheists must not be tolerated, because "the taking away of God, tho but even in thought, dissolves all." If this is what Locke believes, then how can Locke provide common ground for atheists and religious believers?
What Seagrave says about the compatibility of self-ownership and Divine ownership as grounds for natural rights restates what was said by Richard Overton in 1646. Overton was one of the Levellers in the English Civil War. In An Arrow Against All Tyrants, he argued for religious liberty as grounded in "self-propriety"--the property that a man has in himself. But he also assumed that this self-ownership manifested a natural instinct implanted by God, and thus the equality of self-ownership was compatible with the equality of human beings as created in God's image. This could have been the original source for Locke's reasoning. Seagrave does not Overton, however.
THE NEUROSCIENCE OF OWNERSHIP
In his Essay Concerning Human Understanding, Locke identifies 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" (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 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 the activity of the anterior insular cortex (AIC) in constituting the subjective awareness of the individual in caring for one's self and for others to whom one is attached.
This mammalian extension of care to offspring, sexual mates, and other social partners is identified by Locke when he explains human sociality as rooted in the biological inclinations for survival, mating, and reproduction (TT.I.86-89; II.54-56, 77-84).
As intensely social mammals who feel social pain as well as physical pain, and as animals with uniquely human capacities for deliberation, language, and symbolic learning, we develop moral norms expressed in moral sentiments and moral traditions. The idea of "rights" is one way that we formulate these norms as developed through individual and social experience. The modern tradition of "natural rights" or "human rights" manifests that practical experience by which we negotiate the terms of our social life. Natural desires become natural rights when rational creatures reflect on the conditions for satisfying their desires in cooperation with others.
But even if we conclude that evolutionary neuroscience can support a Lockean conception of natural rights as rooted in natural self-ownership, we might wonder about whether this science can also support the Lockean conception of divine ownership.
Since its first formulation by Darwin, evolutionary science has often been assumed to be atheistic. And yet Darwin himself left room for the Divine Creator as First Cause of those original laws of the universe that allowed the natural evolution of life to unfold. Moreover, Darwin recognized the importance of religious belief for moral progress, although he implied that such religious belief was not absolutely necessary.
The Darwinian understanding of the natural moral sense resembles Locke in his appeal to "God and Nature" or Revelation and Reason, so that divine right becomes natural right insofar as Nature's God manifests His will in the way he has "ordered the course of nature" (TT.I.88-90; II.25). We can discern the law of nature by reflecting on our natural experience of the natural world. The atheistic naturalist will not go any further, because the natural order of things will be taken as the unexplained ground of all explanation. But the religious believer will look beyond nature to nature's God as the unexplained ground of all explanation. Darwinian science neither affirms nor denies such religious beliefs. But it does affirm that the moral and political order of life can be rooted in evolved human nature without any necessity for religious belief.
NATURAL RIGHTS AND NATURAL LAW
Whether Darwinian natural right can reconcile Thomistic natural law and Lockean natural rights requires more commentary than I can provide here. But I will offer one comment on what Seagrave says about comparing natural law and natural rights.
Seagrave contrasts the "objective moral standard" of traditional natural law with the "subjective rights" of individuals in the Lockean teaching. Here he follows the lead of Strauss, and in doing that, he makes Strauss's mistake in failing to see that we can affirm the objectivity of the generic goods rooted in human nature, while also affirming the individuality in the expression of those generic human goods by particular individuals.
Darwinian natural right supports this by recognizing the universal natural desires of evolved human nature, while also recognizing the individualized expression of those natural desires in the personal life of human beings. In my argument, the twenty natural natural desires constitute the objective standard of the human good. But each individual will organize and rank those natural desires in a manner that is appropriate for the individual.
We can recognize the liberal regime as the best regime because it secures the conditions in which individuals are free to organize their social lives in the pursuit of the objective goods of human life without coercive enforcement of any one conception of the good upon all.
This is what I have defended in some previous posts as Aristotelian liberalism, which combines Aristotelian social virtue and Lockean political liberty.
FROM METAPHYSICAL ETHICS TO EMPIRICAL ETHICS
As I have indicated in some previous posts, we can see in Locke's appeal to two principles--"divine workmanship" and "self-ownership"--the tension between metaphysical ethics and empirical ethics. If human beings are created by God in His Image, then they have a divinely created worth that cannot be properly denied by those who would deprive them of their sacred rights. But if each human being is naturally inclined to take possession of himself in mind and body, and if each man can see that all other men assert the same self-possession, then this human experience of self-ownership could be a purely secular ground of human rights. The modern move towards understanding human rights as rooted in the secular experience of empathy and moral emotions relies on Locke's secular principle of self-ownership without the religious principle of divine workmanship.
A Darwinian moral psychology and modern neuroscience can explain this secular history of human rights as an extension of the empathetic or sympathetic bonds that have evolved for mammalian social life. Locke anticipated this in so far as he stressed the natural sociality of human beings as a species that cannot survive or reproduce without extensive and intensive parental care of offspring.
S. Adam Seagrave, "Self-Ownership vs. Divine Ownership: A Lockean Solution to a Liberal Democratic Dilemma," American Journal of Political Science, 2011.
Seagrave, "How Old Are Modern Rights? On the Lockean Roots of Contemporary Human Rights Discourse," The Journal of the History of Ideas 72 (April 2011): 305-327
Some of my posts on related themes can be found here, here, here, here, here, here, here, here, here, here, here, here, here, and here.