Thomistic Political Thought

Here is my article "Thomistic Political Thought" for the Encyclopedia of Political Thought:

Thomas Aquinas (1225-1274) was the most important philosopher and theologian of the High Middle Ages.  Thomistic political thought shows his enduring influence on the history of political thought, particularly in the philosophical interpretation and practical application of his teaching on natural law.

          Thomas was an Italian priest who joined the new Dominican order of the Catholic Church.  He taught at the University of Paris and elsewhere.  Of his many writings, the best known is his Summa Theologica (Summary of Theology), which he wrote as a textbook of theology for young students.  After his death, he was canonized by the Church as a saint; and eventually he was recognized by the Church as an authoritative source of Christian philosophy and theology.

          During his lifetime, Thomas’s thinking was influenced by three major controversies.  One was the question of how to reconcile the temporal authority of political rulers and the spiritual authority of the Church.  The second controversy was whether the pagan philosophy of Aristotle could be harmonized with Christian theology.  The third controversy was about how the Church should respond to heretical groups—particularly, the Cathars (or Manicheans)—that claimed to represent a pure form of Christianity free from the corruption of the Catholic Church.

          In response to such controversies, Thomas’s fundamental teaching was the harmony between the natural truths known by human reason and the supernatural truths known by faith in Christian revelation.  A crucial part of this teaching was the idea of natural law.

According to Thomas, there are four kinds of law.  Eternal law is the law of the universe by which God governs everything as created by Him.  Natural law is that part of the eternal law that can be known universally by natural reason and natural inclinations.  Human law is constituted by those particular rules enacted by human lawmakers for particular communities.  Divine law is constituted by God’s commands in the Bible that guide the conduct of Biblical believers according to eternal law beyond what could be done by natural and human law.

In explaining natural law, Thomas indicats that “the order of our natural inclinations ordains the precepts of the natural law” (ST, I-II, q. 94, a. 2).  There are three levels in this order of the natural inclinations.  At the first level, all substances have a natural inclination to preserve themselves.  Consequently, whatever preserves human life and avoids threats to human life is of natural law.  At the second level, human beings share some natural inclinations with some animals, particularly the inclinations to sexual mating and the rearing of offspring.  This shows, in the words of an ancient Roman lawyer, that natural right is “what nature has taught all animals.”  At the third level, human beings have natural inclinations that are proper to their rational nature.  “For example, human beings by nature have inclinations to know the truth about God and to live in society with other human beings.  And so things that relate to such inclinations belong to the natural law—for example, that human beings shun ignorance, that they not offend those with whom they ought to live sociably, and other such things.”  Consequently, “everything to which human beings are inclined by their nature belongs to the natural law” (ST, I-II, q. 94, a. 3).

The major themes of Thomistic political thought can be understood as responses to five prominent objections to Thomistic natural law coming from the critics of Thomism.  The first objection is that Thomistic natural law is not truly natural because it depends on religious faith in the supernatural teachings of the Bible.  The second objection is that natural law reasoning commits the naturalistic fallacy by illogically inferring moral values from natural facts.  The third objection is that the fixed principles of natural law fail to allow for flexibility in judging what is best for particular individuals in variable social circumstances.  The fourth objection is that Thomas was a medieval monarchist whose political teaching is therefore opposed to modern liberal democracy as aiming at the securing of individual liberty.  The fifth objection is that Thomistic natural law supports some unreasonable doctrines of the Catholic Church concerning sexuality, abortion, and marriage.

Reason and Revelation

The first objection arises from the apparent contrast between reason and revelation.  Even if there is a natural inclination “to know the truth about God,” that is not the same as knowing God.  Faithful acceptance of God and of the Bible as His revelation requires a faith that goes beyond natural reason (ST, II-II, q. 2, aa. 1-2).  So if natural law is to be comprehensible by natural reason alone, natural law should not depend upon religious faith.  And yet Thomas often seems to present natural law as if following natural law depended upon understanding it to be God’s law.  The very term “natural law” would seem to presume a divine “lawgiver.”  This has provoked Leo Strauss (1953: 163-64) and others to object that a natural law that depends upon religious faith is not really natural if it assumes faith in the supernatural, and thus it cannot be known by unassisted natural reason alone.

          Some Thomists have explained that, indeed, Thomas’s understanding of natural law is inseparable from his Christian theology.  Fergus Kerr argues: “when Thomas reaches the question of natural law, it is long after he has put in place his theology of beatitude and virtue; he takes natural law to be self-evidently participation in divine providence and always already requiring deeper instruction by the Law of Moses and by ‘the Law of the Gospel’” (2002: 113).

          On the contrary, other Thomists have argued, natural law must stand on its own natural ground independently of divine law.  Therefore, Thomas’s natural law is comprehensible by purely natural reason and experience without any need for faith in the supernatural.  Anthony Lisska (1996) takes this position in interpreting Thomistic natural law as rooted in human nature understood as the natural biological inclinations of human beings.  Thus, Thomistic natural law manifests a biological understanding that might be confirmed by modern biological science.  Thomas thought that “everything is good so far as it is desirable, and is a term of the movement of the appetite” (ST, I, q. 5, a. 6).  If the good is the desirable, and if our evolved human nature is constituted by a set of natural desires distinctive to the human species, then those natural desires could be the biological ground for a natural law that is knowable by natural experience without any need for religious belief (Arnhart 2001).  In his biological reasoning about natural law, Thomas was influenced by the biological work of Albert the Great, his teacher at the University of Paris, who wrote a massive survey of zoology, beginning with Aristotle’s biological writings.

          As an example of such biological reasoning, Thomas explains that marriage is natural because it satisfies natural desires that human beings share with some animals (ST, II-II, q. 57, a. 3; suppl., q. 41, a. 1).  In the Summa Contra Gentiles (SCG), he speaks of the human inclination to marriage as a “natural instinct of the human species” (3.123).  The primary natural end of marriage is to secure the parental care of children; the secondary natural end is to secure the conjugal bonding of male and female for a sexual division of labor in the household.  Among some animals, Thomas observes, the female can care properly for her offspring on her own, and so there is no natural need for any enduring bond between male and female.  For those animals whose offspring do require care from both parents, however, nature implants an inclination for male and female to stay together to provide the necessary parental care (SCG, 3.122-23).  Just as is the case for those animals whose offspring could not survive or develop normally without parental care, human offspring depend upon parents for their existence, their nourishment, and their education.  Even if they do not have children, however, men and women naturally desire marital union because, not being self-sufficient, they seek the conjugal friendship of husband and wife sharing in household life.

The Naturalistic Fallacy

If natural law is rooted in the natural inclinations that constitute human nature, then natural law reasoning is open to the objection that it commits the naturalistic fallacy, because it infers moral values from natural facts.  Many contemporary philosophers have assumed that one cannot logically infer what ought to be from what is.  From the natural fact that human beings desire something, it does not follow that they ought to desire it.

          John Finnis has argued that this does not refute natural law because natural law is not inferred from human nature (1980: 33-36).  The basic forms of human good in natural law are grasped by practical understanding as self-evident and indemonstrable principles, and thus there is no inference from human nature.  Some defenders of natural law have criticized Finnis for proposing “natural law without nature.”  Finnis has responded by arguing that while moral norms are grounded in human nature, these norms are not inferred from a prior knowledge of human nature.  The practical reasonableness of the first principles of action depends on some rational apprehension of natural inclinations as good.

          Ralph McInerny suggests another way of responding to the objection that Thomistic natural law commits the naturalistic fallacy.  Thomas does not absolutely separate facts and values.  For Thomas, the good is the desirable.  Every purposive human action implicitly involves the judgment that what we seek to accomplish through this action will be desirable in the sense of truly perfecting or fulfilling us.  Consequently, the judgment that we ought to desire what is truly perfective of us is already present in any given desire.  There is no purely factual desire separated from prescriptive desire—hence, there is no fact-value dichotomy.

 

The Need for Prudence

Does this grounding of natural law in human nature assume a universal and unchanging human nature?  Does this ignore the great variability in the lives of diverse individuals in diverse societies?  This suggests a third objection to Thomistic natural law—that the fixity of Thomas’s universal principles of natural law does not allow for flexibility in judging what is best for this individual in this situation.

          Cultural diversity seems to deny any universal natural law.  There seems to be hardly any moral practice of any society that has not been rejected by some other society.  We might conclude, therefore, that everything is culturally relative, and that there are no moral absolutes.

          Thomas recognizes the need for flexibility in practical judgment, which requires the virtue of prudence.  “The general principles of the natural law cannot be applied to all men in the same way on account of the great variety of human affairs, and hence arises the diversity in the positive laws among various people” (ST, I-II, q. 95, a. 2, ad 3). 

Family law illustrates this.  By nature human beings are inclined to produce offspring who need prolonged and intensive care by adults.  By custom, societies have devised diverse ways of organizing the division of labor in caring for the young.  By stipulation, lawmakers specify the legal rights and duties of parents and children in a particular community.  To be successful these legal stipulations must respect both natural inclinations and customary practices, although this leaves the lawmakers free to choose among a wide array of practicable rules.  Thus, natural law constrains but does not determine customary law and positive law.

 

Natural Law and Liberal Democracy

One way to achieve moral flexibility in response to individual variation and cultural diversity is to create a liberal society that protects individual liberty and cultural pluralism.  Individuals can be free to live as they please in cooperation with other consenting adults so long as they don’t harm anyone else.  Modern liberal democracy tries to do this by having governments established by the consent of the governed to secure individual rights.

Critics of Thomism object, however, that Thomas seems to be hostile to liberal democracy, because he endorses monarchy as the best form of government, and because he thinks that the purpose of government is not to protect individual rights but to enforce a shared morality on the whole community.

Thomists like Jacques Maritain and Yves Simon have tried to show that Thomas’s teaching is compatible with modern liberal democracy and with the modern conception of human rights.  Some Thomists like John Hittinger (2002: 35-60) have argued, however, that Maritain and Simon fail to find an unqualified endorsement of pure democracy in Thomas’s writings.

Nevertheless, as Hittinger and others have suggested (Blythe 1992), one can rightly interpret Thomas as teaching that the best regime is a mixed government that combines monarchic, aristocratic, and democratic elements (ST, I-II, q. 105, a. 1).  Modern liberal democratic republicanism belongs to this tradition of mixed government as the best regime.

Moreover, Thomas is surprisingly liberal in his argument that it is improper for human law to try to enforce perfect virtue: “Human law is framed for a number of human beings, the majority of whom are not perfect in virtue.  Wherefore, human laws do not forbid all vices from which the virtuous abstain, but only the more grievous vices from which it is possible for the majority to abstain, and chiefly those that are to the hurt of others, without the prohibition of which human society could not be maintained.  Thus, human law prohibits murder, theft, and suchlike” (ST, I-II, q. 96, a. 2).

Sexuality, Abortion, and Marriage

A final objection to Thomistic natural law—perhaps the most contentious one—is that natural law is rendered dubious by the way it is used by the Catholic Church to justify its doctrines about sexual behavior, abortion, and marriage.  The Church condemns abortion as murder, and thus contrary to the natural law principle that innocent life is to be preserved.  The Church also condemns non-reproductive sexual conduct as contrary to the natural law principle that the sexual organs are naturally oriented to producing children.  Homosexual conduct and homosexual marriage are therefore condemned as unnatural.

Some Thomists have indicated that Thomas never condemns intentional abortion as murder.  Furthermore, he never says that life begins at conception, because he agrees with Aristotle that human life begins sometime after the first month of gestation.  These Thomists argue, however, that if Thomas had had the knowledge of modern embryology, he would have concluded that human life begins with the fertilization of a human egg, because that initiates the genetic potential for a unique human person to develop (Haldane and Lee 2003).

Thomas declares that life-long monogamous marriage is dictated by natural law, because human offspring are born dependent on the care of both a mother and a father.  And yet Thomas concedes that there are exceptional cases.  A wealthy woman might rear her children without the help of the father; and a man producing a child through fornication might provide for the rearing of the child (ST, II-II, q. 154, a. 2; SCG, 3.122.7).

Thomas agrees with the Biblical condemnation of homosexuality as unnatural (ST, I-II, q. 94, a. 3, ad 2; II-II, qq. 153-54).  Homosexual marriage is unnatural in so far as it cannot achieve the primary natural end of marriage—procreation and parental care.  But homosexual marriage might achieve the secondary natural end of marriage—conjugal bonding—which is also true for infertile heterosexual marriages.  Thomistic opponents of homosexual marriage must argue that infertile heterosexual marriages are still natural marriages, because they are inherently oriented to producing children, even when they fail to produce any children (Girgis, George, and Anderson 2010).

Even if one regards homosexuality as a vice, one might agree with Thomas that it is not the proper role of human law to enforce perfect virtue, and that human law should be concerned primarily with prohibiting conduct that is harmful to social order, such as murder and theft.

Some Thomists assume that social order requires marriage as a formal, public institution created by marriage licensing law.  But if marriage really does satisfy some of the deepest natural desires, as Thomas argued, why could we not privatize marriage just as we have privatized religion, so that marriage would then stand on its own natural ground independently of government?  In fact, throughout most of human history, marriage has been an informal social institution based on the consent of individuals and their families, without any formal licensing by the state or the church (Koontz 2005).  Privatizing marriage would recognize it as ultimately rooted not in human law or divine law but in natural law.

 

References and Suggested Readings

 

Aquinas, T. (2002) On Law, Morality, and Politics. Trans. R. J. Regan. Indianapolis, IN: Hackett Publishing.

Arnhart, L. (2001) “Thomistic Natural Law as Darwinian Natural Right.” In E. F. Paul, F. D. Miller, and J. Paul (Eds.), Natural Law and Modern Moral Philosophy. Cambridge: Cambridge University Press.

Blythe, J. M. (1992) Ideal Government and the Mixed Constitution in the Middle Ages. Princeton, NJ: Princeton University Press.

Finnis, J.  (1980) Natural Law and Natural Rights. Oxford: Clarendon Press.

Girgis, S., George, R., and Anderson, R. (2010) “What is Marriage?” Harvard Journal of Law and Public Policy, 34 (1): pp. 245-287.

Haldane, J., and Lee, P. (2003) “Aquinas on Human Ensoulment, Abortion, and the Value of Life,” Philosophy, 78: pp. 255-278.

Hittinger, J. (2002) Liberty, Wisdom, and Grace: Thomism and Democratic Political Theory. Lanham, MD: Lexington Press.

Kerr, F. (2002) After Aquinas: Versions of Thomism. Malden, MA: Blackwell.

Koontz, S. (2005) Marriage, a History. New York: Viking.

Lisska, A. J. (1996)  Aquinas’s Theory of Natural Law: An Analytic Reconstruction. Oxford: Clarendon Press.

Maritain, J. (1951) Man and the State. Chicago: University of Chicago Press.

McInerny, R. (1982) Ethica Thomistica: The Moral Philosophy of Thomas Aquinas. Washington, DC: Catholic University of America Press.

Rommen, H. A. (1998)  The Natural Law: A Study in Legal and Social History and Philosophy. Trans. T. R. Hanley. Indianapolis, IN: Liberty Fund.

Simon, Y. R. (1951) Philosophy of Democratic Government. Chicago: University of Chicago Press.

Strauss, L. (1953)  Natural Right and History. Chicago: University of Chicago Press.