Annals of Ethics
Online ISSN : 2434-4699
The volitional basis of moral duty in Thomas Aquinas
Shibamoto Kohei
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2018 Volume 67 Pages 105-117


This paper proposes to elucidate the volitional basis of deontology in Aquinas’s ethics.
 We analyze the concept of commanding(imperare)as a clue to this purpose. In the Summa Theologiae I-II, Question 17, Article 1, Aquinas says that to command is essentially an act of reason, based on an act of will because reason’s role is to order another to do something by way of intimation. Although the will can be commanded by reason, the mutual series between will and reason cannot proceed ad infinitum. Aquinas says that the first act of will comes not from reason, but from an “instinct” of a higher cause, i.e., God.
 Aquinas believes that the first act of will is necessarily to intend the ultimate end, which means perfect good. Human beings can freely select any other end and any other means than the ultimate end, in comparison with what perfect good means.
 In the Summa Theologiae I-II, Question 94, Article 2, Aquinas suggests the first precept of natural law is unconditional duty, saying “good ought to be done and pursued and evil ought to be avoided.” We can interpret this precept in greater detail by saying that because the will necessarily intend the ultimate end, human good, which is ordered to the ultimate end by reason, ought to be done.
 Moreover, the characteristic of duty remains in the virtuous act, even that of charity(caritas), a theological virtue infused by God’s grace. This is because it is necessary for human beings to intend the ultimate end until attaining it by seeing God’s essence directly, something impossible in this life.
  In conclusion, we can say that the first act of will, i.e., necessarily intending the ultimate end, is the volitional basis of deontology in Aquinas’s ethics.

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© 2018 The Japanese Society for Ethics
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