Treatise on Law

Question 90: On the essence of law

Question 91: On the types of law

Question 92: On the effects of law

Question 93: On eternal law

Question 94: On natural law

Question 90: On the essence of law
    90, 1-4: St. Thomas here delineates the four defining characteristics of law: 
      (i) a dictate of practical reason, 
      (ii) ordered toward the common good, 
      (iii) made by one who has care for the community, and 
      (iv) promulgated. 

Question 91: On the types of law

    91,1: Eternal Law = the order of divine providence as promulgated from eternity by God, according to which each rational and non-rational creature is ordered toward the good of the universe. 

    91,2: Natural Law = a certain participation in eternal law insofar as we have providence over ourselves and others and can order ourselves and others toward the good of our nature; the light of natural reason whereby we discern what is good and evil--which pertains to natural law--is nothing other than the imprint of the divine light in us.  (The precepts of the natural law are best studied in connection with Question 100 on the moral precepts of the Old Law.) 

    91,3: Human Law = particular statutes instituted in accord with human reason for the good of civil society. 

    91,4: Divine Law = revealed law, which leads us toward our supernatural end, gives us certitude with respect to what is to be done and what it is to be avoided, governs our interior acts as well as our exterior acts, and guarantees that no sin at all is unprohibited and unpunished. Divine law is divided into the Old Law and the New Law, which are related as child (imperfect) to adult (perfect). They differ with respect to end (sensible and earthly goods vs. intelligible and heavenly goods), subject matter (exterior acts vs. interior acts), and motivations for obeying the law (fear vs. love). 

    91,5: Law of the fomes: In us the fomes peccati--i.e., the inclination of sensuality, which is natural to brute animals--is a punishment for sin and thus falls under the notion of law.

Question 92: On the effects of law

    92,1: It is an effect of law to make us good, since obedience to law causes acquired virtue, both disposing us toward infused virtue and helping us conserve and promote already possessed infused virtue

    92,2: The four effects of law are:

      (i) precept (command) 
      (ii) prohibition 
      (iii) permission, and 
      (iv) punishment.

Question 93: On eternal law

    93,1: The notion of divine wisdom has two aspects with respect to the created world:
      Creation: with respect to creation God is an artist and so his wisdom has the character of an art or exemplar or idea, through which the world is created as God's artifact.
      Governance: with respect to governance God is the ruler of the movements of things and so his wisdom has the character of an eternal law according to which he directs the world. 

    93,2-3: This eternal law is known to all rational creatures at least to some extent through its effects, and it is known in itself to God and the blessed. What's more, because of its primacy, eternal law is such that all other law (natural, divine, human, and even the law of sin insofar as it is a form of punishment) derives from it. 

    93,4-6: As for the contents of eternal law, only what could have been but need not have been, absolutely speaking, is subject to eternal law, and so eternal law does not include metaphysical necessities or impossibilities. But all contingencies are contained in eternal law. God directs contingent beings by impressing on them the principles of their own acts and (in the case of rational creatures) an understanding of divine precepts. So human beings participate in eternal law in two ways: (i) through cognition and (ii) through action and passion (i.e., through moving principles). The former is distinctive of rational creatures, whereas the latter pertains to rational and non-rational creatures alike. Further, the virtuous, who are aided by faith and grace, participate in eternal law in a more perfect way than the vicious, in whom both the inclination to virtue and the knowledge of good and evil are obstructed.

Question 94: On natural law

    94,1: Natural law consists of precepts that are the object of a natural habitual cognition (synderesis), which is to the practical order what the understanding of first principles (intellectus) is to the speculative order. 

    94,2: The natural law is founded on the first principle of law, viz., Good is to be done and pursued, and evil is to be avoided, which plays a role in the practical sphere similar to that of the principle of non-contradiction in the speculative or theoretical sphere All the material precepts of natural law have to do with what practical reason naturally apprehends as human goods--the conservation of individual existence, the conservation of the species (e.g., sexual intercourse and the education of offspring), and the good of reason (e.g., knowledge of the truth about God and living together in society).  In the section on the moral precepts of the Old Law St. Thomas distinguishes three levels of the precepts according to the level of evidentness they have.  First level: love of God and neighbor; second level: precepts of the Old Law (Ten Commandments), which specify the first level; third level: precepts discerned by the wise that specify the second level. 

    94,3: Since reason naturally apprehends as a human good a life led in accordance with reason, all acts of virtue pertain to natural law. This is not to say, however, that natural law prescribes every particular act of virtue, since not every act of virtue is such that we are naturally inclined to it by our primary inclination to the human good. Rather, inclinations to such acts result from our knowledge of natural law and our inquiry into alternative ways of living well as human beings within the parameters of the law. (This is where third-level precepts are especially important.) 

    94,4: Natural law has to do with those things to which man is naturally inclined, and among these inclinations is the inclination to act according to reason. Reason proceeds from the more general to the more particular. Practical reason descends from quasi-necessary general principles to more and more particular considerations--this is why certain general rules are subject to exceptions. So even though the general practical principles are right and true and equally known by everyone, it is not the case that with respect to particulars the same thing is practically true or right in all situations or that what is right is equally known to everyone. And even for those for whom the same thing is right with respect to particulars, what is right is better known to some (the wise) than to others. For instance, everyone knows that in general what has been borrowed ought to be returned. But it takes practical wisdom to recognize situations in which it would be contrary to reason--and hence wrong--to return what has been borrowed (recall the Republic). For it takes wisdom to distinguish between circumstances that are and circumstances that are not morally relevant. And such wisdom is acquired in part through living well. 

    More generally, in question 100, on the moral precepts of the Old Law--which precepts St. Thomas takes to be a revelation of the natural law--he distinguishes three levels.  First are the two fundamental precepts of the natural law:  (a) to love God above all other things and (b) to love one's neighbors as oneself.  The second-level precepts are the specification of these two precepts in general principles, as revealed by the Ten Commandments.  The third-level precepts are not as evident as the first two and demand wisdom and experience in order to be known and prudently applied.  (The above example is relevant here.) 

      "So one should say that with respect to the first general principles, the natural law is the same for all, regarding both what is right and knowledge of what is right. But with respect to certain particulars, which are quasi-conclusions drawn from the general principles, the natural law is the same for all in most cases, regarding both what is right and knowledge of what is right. But in a few cases [these conclusions] can be wrong, because of some particular impediments (just as generable and corruptible natures have defects in a few cases, because of impediments), or even unknown (and this because some have a reason that has been corrupted by passion or bad habit--e.g., as Julius Caesar reports in The Gallic Wars, among the Germans theft was at one time not considered wrong, even though it is expressly contrary to the natural law.)"
    94,5-6: Natural law cannot change by subtraction, although it can be added to in accordance with divine and human laws which, while not violating natural law, prove useful for human life. Also, no matter how corrupt an individual or society becomes, the most general principles of natural law cannot be erased from the human heart--even though, as we have seen, reason can be impeded by passion from applying these general principles in particular situations. But other, secondary, precepts can be erased from the human heart by bad but persuasive arguments and also by depraved customs and corrupt habits. (Here St. Thomas refers to Romans 1.)