Many difficulties and concerns have surrounded the theory of natural law. For example, some believe that natural law theory is too simple a concept and that it collapses into complicated scenarios. Over the centuries, the theory of natural law has been extended, criticized and applied to the theory of philosophy and even to existing legal and political structures. A more interesting argument has recently been taken up by Brian Bix (1996). Following John Finnis (1980), Bix rejects the interpretation of Aquinas and Blackstone as conceptual naturalists, arguing instead that the claim that an unjust law is not a law should not be taken literally: Because natural law as an ethical theory can be understood as an extension of the scientific and rational study of the functioning of the world, The laws of economics can be understood as natural laws of how economies “should” work. Moreover, the practice of applied economics must be based, at least implicitly, on certain ethical assumptions in which economic analysis is used to dictate (or prohibit) public policy or how corporations should behave: man does not learn natural law per se, but we “discover” it by constantly making choices for good rather than evil. Some schools of thought believe that natural law is transmitted to man by a divine presence. The theory of natural law was known to the ancient Greeks, but was later developed by many philosophers. Some important philosophers who played a role in the development of natural law include Aristotle, Plato, and Thomas Aquinas. To begin with, it is important to distinguish two types of theory known as natural law.

The first is a theory of morality, which is roughly characterized by the following theses. First, moral propositions have what is sometimes called objective, in the sense that such statements carry the value of objective truth; That is, moral statements can be objectively true or false. Although moral objectivism is sometimes equated with moral realism (see, for example, Moore 1992, 190: “The truth of any moral statement lies in its conformity with a moral reality independent of spirit and convention”), the relationship between the two theories is disputed. Geoffrey Sayre-McCord (1988), for example, views moral objectivism as a kind of moral realism, but not as the only form; According to Sayre-McCord, moral subjectivism and moral intersubjectivism are also forms of moral realism. Strictly speaking, the moral theory of natural law is therefore engaged only in the objectivity of moral norms. Therefore, Bix interprets Thomas and Schwarzstein as views similar to the neonaturalism of Johannes Finnis, which is discussed later in Section III. Yet while a plausible argument can be made for Bix`s view, the long history of interpreting Thomas Aquinas and Blackstone as conceptual naturalists, as well as their pedagogical value in the development of other legal theories, ensures that this practice is likely to continue indefinitely. The second thesis, which is at the heart of the moral theory of natural law, is the assertion that moral norms are somehow derived or implied by the nature of the world and the nature of man.

St. Thomas Aquinas, for example, identifies the rational nature of man as what defines the moral law: “The domination and measure of human actions is reason, which is the first principle of human action” (Thomas Aquinas, ST. I-II, Q.90, A.I). Since humans are rational beings by nature, it is morally appropriate that they behave in a manner consistent with their rational nature. Thus, Thomas Aquinas draws the moral law from the nature of man (i.e. from the “natural law”). Natural law consists of those commandments of the eternal law that govern the conduct of beings who possess reason and agency. The first commandment of natural law, according to Thomas Aquinas, is the somewhat empty imperative to do good and avoid evil. Here it should be noted that Thomas Aquinas advocates a theory of the morality of natural law: what is right and wrong according to Thomas Aquinas derives from the rational nature of man. Thus, good and evil are both objective and universal. A more reasonable interpretation of statements such as “an unjust law is not a law at all” is that unjust laws are not laws “in the fullest sense of the word.” As one might say of a professional who had the necessary degrees and credentials, but still did not seem to have the necessary skills or judgment: “She is not a lawyer” or “he is not a doctor.” It only suggests that we don`t think the title has all the implications it normally has in this case. Similarly, to assert that an unjust law is “not really a law” can only mean that it does not have the same moral force or offer the same grounds of action as laws compatible with the “higher right” (Bix 1996, 226).

Another frequently expressed concern is that conceptual naturalism undermines the possibility of moral criticism of the law; Since conformity with natural law is a necessary condition for legal validity, any applicable law is, by definition, morally just. According to this reasoning, the legal validity of a norm necessarily implies its moral justice. As Jules Coleman and Jeffrey Murphy (1990, 18) have said: Conversely, although unusual, one could accept a theory of natural law without advocating a theory of natural law of morality. One could argue, for example, that the conceptual point of law is partly to reproduce the requirements of morality, but also a form of ethical subjectivism (or relativism). According to this particular view, the conceptual purpose of the law would be to apply standards that are morally valid on the basis of cultural consensus. For this reason, the theory of natural law is logically independent of the theory of morality of natural law. The remainder of this essay will deal exclusively with theories of natural law. It is claimed that the theory of natural law existed without even needing human understanding or any kind of political order or legislation. To be explained further, natural law involves the idea that humans intrinsically understand the difference between “good” and “evil.” In essence, he concludes that humans are not taught about natural laws; They initiate it by making good and good decisions.

Therefore, it is said that it can be found by the exercise of reason. The only formula that could be called the definition of law in these writings is now well known: law is the enterprise of subjecting human behavior to the rule of rules.