Abstract

In lieu of an abstract, here is a brief excerpt of the content:Instinct of Nature: Natural Law, Synderesis, and the Moral SenseRobert A. Greene“Instinct is a great matter.”—Sir John FalstaffThis essay traces the evolution of the meaning of the expression instinctus naturae in the discussion of the natural law from Justinian’s Digest through its association with synderesis to Francis Hutcheson’s theory of the moral sense. The introduction of instinctus naturae into Ulpian’s definition of the natural law by Isidore of Seville in the seventh century posed a problem of definition for medieval commentators. Some said that it meant a universal and providential natura naturans; some defined it as the urge to self and species preservation in animals, degenerating in man into sensual and shameful impulses; some advanced the humanistic and paradoxical notion that it referred to a unique exercise of human reason in coming to know the natural law. The contemporaneous revival in the twelfth century of St. Jerome’s puzzling new term “synderesis,” and its gradual definition as the immediate apprehension of the first practical moral principles of the natural law, brought the two terms into proximity and loose association.A half-century later St. Bonaventure made explicit what had remained latent in the thinking of Thomas Aquinas by relocating synderesis in the affective rather than the intellectual part of man’s nature. Accordingly the moral discoveries of synderesis came to be spoken of as not only non-discursive but instinctive in nature—apprehensions for which no reason could be given, apprehensions somehow rooted in affective human experience. During the bilingual early modern period an increasingly secularized, internalized, and reified instinctus [End Page 173] naturae, together with its abbreviated vernacular cognate, “instinct,” came to serve as a substitute and synonym for the obsolescent synderesis. Edward Herbert’s attention to instinctus naturae in his De Veritate (1624), Sir Matthew Hale’s speculations about the place of rational instinct in the natural law, and Francis Hutcheson’s theory of a moral sense all exemplify this semantic legacy.The first entry in Justinian’s Digest has had a disproportionate influence on later speculation about the natural law. It begins a chapter that gives pride of place to general definitions of justice, law, jus naturale and jus gentium, and it is drawn from the writings of the Roman jurisconsult Domitius Ulpianus (d. 223), whose work constitutes forty percent of the Digest. Ulpian defines the natural law, with insistent repetition, as that which nature has taught to, or is common to, all animals:Jus naturale is that which nature has taught to all animals; for it is not a law specific to mankind but is common to all animals—land animals, sea animals, and the birds as well. Out of this comes the union of man and woman [male and female] which we call marriage, and the procreation of children, and their rearing. So we can see that the other animals, wild beasts included, are rightly understood to be acquainted with this law. Jus gentium, the law of the nations, is that which all human peoples observe. That it is not coextensive with natural law can be grasped easily, since this latter is common to all animals whereas jus gentium is common only to human beings among themselves. 1Justinian’s compilers gave Ulpian’s definition striking prominence at the beginning of the Digest and then in the same short chapter quoted the incompatible and more traditional definitions of his contemporaries Gaius and Paulus. They confined the operation of the natural law to mankind and spoke of reason as its source. 2 The compilers had been charged to eliminate just such conflicts; yet here at the very outset they set a conundrum that perplexed commentators [End Page 174] and invited explanation from Isidore of Seville to Hugo Grotius. Their selection of quotations suggests that as lawyers they regarded such general definitions as “for legal purposes no more than ornament to discussion.” 3 For those of a more speculative bent, however, the dilemmas could not have been more fundamental. How was the natural law to be defined in relation to those appetitive and self-preservative urges that man seemed to share with animals? Or did the term law apply only...