Ethics

See also: Christian ethics

Thomas’s ethics are based on the concept of “first principles of action.”^[75] In his Summa theologiae, he wrote:

Virtue denotes a certain perfection of a power. Now a thing’s perfection is considered chiefly in regard to its end. But the end of power is act. Wherefore power is said to be perfect, according as it is determinate to its act.^[76]

Aquinas emphasized that “Synderesis is said to be the law of our mind, because it is a habit containing the precepts of the natural law, which are the first principles of human actions.”^[77][78]

According to Aquinas “…all acts of virtue are prescribed by the natural law: since each one’s reason naturally dictates to him to act virtuously. But if we speak of virtuous acts, considered in themselves, i.e., in their proper species, thus not all virtuous acts are prescribed by the natural law: for many things are done virtuously, to which nature does not incline at first; but which, through the inquiry of reason, have been found by men to be conductive to well living.” Therefore, we must determine if we are speaking of virtuous acts as under the aspect of virtuous or as an act in its species.^[79]

Thomas defined the four cardinal virtues as prudence, temperance, justice, and fortitude. The cardinal virtues are natural and revealed in nature, and they are binding on everyone. There are, however, threetheological virtues: faith, hope, and charity. Aquinas also describes the virtues as imperfect (incomplete) and perfect (complete) virtues. A perfect virtue is any virtue with charity, charity completes a cardinal virtue. A non-Christian can display courage, but it would be courage with temperance. A Christian would display courage with charity. These are somewhat supernatural and are distinct from other virtues in their object, namely, God:

Now the object of the theological virtues is God Himself, Who is the last end of all, as surpassing the knowledge of our reason. On the other hand, the object of the intellectual and moral virtues is something comprehensible to human reason. Wherefore the theological virtues are specifically distinct from the moral and intellectual virtues.^[80]

Thomas Aquinas wrote “Greed is a sin against God, just as all mortal sins, in as much as man condemns things eternal for the sake of temporal things.”.

Furthermore, Thomas distinguished four kinds of law: eternal, natural, human, and divine. Eternal law is the decree of God that governs all creation. It is, “That Law which is the Supreme Reason cannot be understood to be otherwise than unchangeable and eternal.”^[81] Natural law is the human “participation” in the eternal law and is discovered by reason.^[82] Natural law is based on “first principles“:

. . . this is the first precept of the law, that good is to be done and promoted, and evil is to be avoided. All other precepts of the natural law are based on this . . .^[83]

Whether the natural law contains several precepts, or one only is explained by Aquinas”, All the inclinations of any parts whatsoever of human nature, e.g., of the concupiscible and irascible parts, in so far as they are ruled by reason, belong to the natural law, and are reduced to one first precept, as stated above: so that the precepts of the natural law are many in themselves, but are based on one common foundation.”^[84]

The desires to live and to procreate are counted by Thomas among those basic (natural) human values on which all human values are based. According to Thomas, all human tendencies are geared towards real human goods. In this case, the human nature in question is marriage, the total gift of oneself to another that ensures a family for children and a future for mankind.^[85] To clarify for Christian believers, Thomas defined love as “to will the good of another.”^[86]

Concerning the Human Law, Aquinas concludes, “…that just as, in the speculative reason, from naturally known indemonstrable principles, we draw the conclusions of the various sciences, the knowledge of which is not imparted to us by nature, but acquired by the efforts of reason, so too it is from the precepts of the natural law, as from general and indemonstrable principles, that the human reason needs to proceed to the more particular determination of certain matters. These particular determinations, devised by human reason, are called human laws, provided the other essential conditions of law be observed….” Human law is positive law: the natural law applied by governments to societies.^[87]

Natural and human law is not adequate alone. The need for human behavior to be directed made it necessary to have Divine law. Divine law is the specially revealed law in the scriptures. Aquinas quotes, “The Apostle says (Hebrews 7.12): The priesthood being translated, it is necessary that a translation also be made of the law. But the priesthood is twofold, as stated in the same passage, viz, the levitical priesthood, and the priesthood of Christ. Therefore the Divine law is twofold, namely, the Old Law and the New Law.” ^[88]

Thomas also greatly influenced Catholic understandings of mortal and venial sins.

Thomas Aquinas, refers to animals as dumb and that the natural order has declared animals for mans use. Thomas denied that human beings have any duty of charity to animals because they are not persons. Otherwise, it would be unlawful to use them for food. But this does not give humans the license to be cruel to them, for “cruel habits might carry over into our treatment of human beings.”^[89][90]

Thomas contributed to economic thought as an aspect of ethics and justice. He dealt with the concept of a just price, normally its market price or a regulated price sufficient to cover seller costs of production. He argued it was immoral for sellers to raise their prices simply because buyers were in pressing need for a product.^[91][92]