Cicero and Aquinas

A Comparative Analysis of Cicero and Aquinas: Nature and the Natural Law

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Charles P. Nemeth
Bloomsbury Studies in Ancient Philosophy
  • New York, NY: 
    Bloomsbury Academic
    , May
     208 pages.
     For other formats: Link to Publisher's Website.


In his learned and carefully argued book, Charles Nemeth compares the respective views of a lawyer-philosopher born more than a century before Christ with those of the thirteenth century Christian philosopher and Dominican priest, St. Thomas Aquinas. He lays out a remarkable number of similarities while also pointing out some significant differences.

Although Aquinas considered theology to be the perfect science because it is founded upon divine revelation and thus has the most certain principles, he never subscribed to the Averroist position that there could be two truths, one based on natural principles and one based on theology. Rather, faith and reason, for Aquinas, were compatible and complimentary and, as he wrote in the very first question of his magnum opus, even the theologian makes use of the effects of God in nature (Summa Theologica, q. 1 a.7). This fact seems to account for some of the overlap between Aquinas and Cicero, because they both had great respect for nature. As Nemeth says, "for both thinkers, nature and the natural order is a series of instructions that contribute to a comprehensive view of what the natural law is" (x).

The two thinkers were even similar in their understanding of God as being the one who guides nature to provide its observable normativity. In the case of Cicero, even though nature provides the blueprint for the "conduct of life" (26), he departed from the Stoics, as Nemeth rightly observes, because he did not see "God and nature as one and the same" but rather proposed "a God that is metaphysically transcendent" (25). Because of this, Cicero seemed to see nature itself as able to provide the norms that lead the creature to his or her true happiness, just as Aquinas did.

The similarities of the two philosophers are most pronounced on the level of principle. Nemeth suggests that they both traveled "a road that aligns, intersects, or even replicates the other" (20). In the third chapter, Nemeth demonstrates the central role of reason in establishing the universal and consistent laws inherent in nature itself for these two thinkers, and in chapter 4, he goes into more detail about particulars. At this point, it becomes clear that "the natural law theory of Cicero is really in its infancy stage when compared with the life and times of St. Thomas" (122), because Thomas has a more fully developed theory. Nevertheless, Nemeth argues that seven principles can be found in the work of both of the authors:

1. A natural law emanates from a Creator;

2. The imprint or reflection of a natural law is impressed on every human being;

3. The precepts, inclinations, and dispositions of natural law are identifiable;

4. The natural law is universal and unchangeable;

5. The natural law is rooted in reason and not the will, passions, or appetites;

6. The natural law is the same for every person;

7. The natural law is superior to every human law, though subservient and dependent upon a higher eternal or divine law. (123)

The fifth chapter explicitly investigates the question of the compatibility of the two authors' theories and does so by delving further into particulars. What we find, again, is that Cicero's theory is less detailed, even though it was able to "deliver a natural law schema that will support the eventual infrastructure that St. Thomas will build upon" (135). Cicero does diverge from Thomas on some specific matters, and these are rather significant. Infanticide and suicide, for instance, can in some cases be justified for Cicero, whereas Aquinas would never countenance such acts (140, 150).

All things considered, this is an excellent book that is well worth the read. The topic itself is fascinating and the learned author's familiarity with both Cicero and Aquinas is impressive. The book suffers from a number of typographical errors and insufficiently cited quotations or concepts (sometimes a work such as the whole of the Summa or De Legibus is cited without any particular section or page; see 175, for example), but it remains an erudite exposition of both authors' understanding of nature and the natural law. There seems, in fact, to only be one instance in which Nemeth’s analysis is less than helpful. Nemeth goes into some detail in regard to the question of abortion, and argues that Aquinas would not consider abortion to be seriously opposed to the natural law if it were to take place in order to "save the life of the mother" (139). He provides no direct quotes to support this claim although he directs the reader to question 90 of the First Part of the Summa, which says nothing about either abortion or mothers. He thus not only fails to take into consideration recent scholarship arguing otherwise, but also places words in Aquinas's mouth that are not found in any of the places Aquinas actually refers to abortion. With this one exception, the book is an excellent read which provides fascinating biographical information in a very reader-friendly format.

About the Reviewer(s): 

Ryan J. Brady is an adjunct professor of classics and early Christian literature at Ave Maria University.

Date of Review: 
October 3, 2017
About the Author(s)/Editor(s)/Translator(s): 

Charles P. Nemeth is professor and department chair of legal studies, City University of New York.


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