The Concepts of Self-Evidence in the Finnis Reconstruction of Natural Law

St. Mary’s Law Journal, Vol. 50:101, 2020

58 Pages Posted: 11 Dec 2019

Date Written: November 24, 2019


John Finnis’s natural law theory is widely influential, particularly among conservative Catholic legal scholars. Finnis, who was the advisor for Neil Gorsuch’s doctorial dissertation, accepts the separation of fact and value advanced by legal positivists. To avoid the conflation of fact and value, he argues that the moral claims of natural law are justified by the self-evident first principles of practical reason (these basic first principles are referred to in this essay as the “Basic Goods”). His cardinal example of such a first principle is the claim that the pursuit of knowledge is a cause for action.

He says that the validity of this claim is self-evident, by which he means that anyone who knows what knowledge is, knows immediately that knowledge is good to have in abundance and worthy of pursuit. Thus, the validity of the claim is self-evident in the sense that it is immediately grasped by the intellect and not derived from some other standard of validity (such as an empiricism) or from more basic claim (such as a factual claim). Since the moral meaning of the Basic Goods is self-evident on Finnis’ account, he argues that they do not conflate facts and values, since they are wholly disclosed to the immediate awareness by practical reason.

While much has been written about various aspects of Finnis’s reconstruction of natural law, little attention has been given to his concept of self-evidence itself. But since the claim of self evidence is the justification for first principles that are the foundation for the entire theory of natural law, a closer inspection of it is warranted.

My essay shows that Finnis actually makes use of two distinct conceptions of self-evidence. One is medieval ( coming primarilly from thought of Thomas Aquinas). The other conception comes from modern symbolic logic (Finnis cites to David Hilbert), which is concerned with abstract relations.

There is a critical difference between them: the medieval and modern philosophers differ in their conceptions of self-evidence. The medieval conception presupposes that words are, in some sense, about beings (ens) that actually exist (in actu). Therefore, logical propositions are claims about relations between and among existing objects. For example, the truth of the principle of non-contradiction is the claim that a being might either actually exist (or not exist) speaks for itself (per se nota) because it is immediately grasped as true by the intellect. For example, to the medieval mind, the claim that my coffee mug is sitting on the table in front of me is self-evident if it can be observed to be so. The modern conception, however, does not presuppose actually existing things. In modern logic, propositions are formal relations among abstract symbols. They do not anticipate that there is any actual entity that exists in correspondence to the symbols. For example, the identity principle (A=A) does not require any actual entity corresponding to A for the logical proposition to be valid.

My essay argues that Finnis equivocates between the medieval and modern understandings of logic. Sometimes, he wants self-evident principles to refer to real things so they can have moral significance. (For example, the claim that knowledge is good would be meaningless unless knowledge and good were extrinsic concepts). At other times, he wants self-evidence to be a formal relation without reference to the facts of actual entities in the world (intrinsic), so that the separation of fact and value can be maintained.

Neither the medieval concept (extrinsic) nor the modern concept (intrinsic) serves the purposes he seeks for the grounds of the natural law. Self-evidence as it is understood by medieval philosophers conflates fact and value, and the modern concepts of self-evidence (intrinsic) are inadequate as the justification for a normative claim because it is only abstract and formal. Thus, neither concept is adequate for his reconstruction of the natural law, since he needs a concept of self-evidence that can avoid the naturalistic fallacy, as a modern concept can, but also can ground axiological ethics (a theory of the good), which the medieval concept can. Alone, neither concept can do both. So, for the theory to work, he must equivocate between incompatible concepts.

Keywords: Jurisprudence, Natural Law, Finnis, Legal Philosophy, Logic, Medieval Philosophy, Philosophy Of Mathematics

Suggested Citation

Lee, Kevin Paul, The Concepts of Self-Evidence in the Finnis Reconstruction of Natural Law (November 24, 2019). St. Mary’s Law Journal, Vol. 50:101, 2020, Available at SSRN:

Kevin Paul Lee (Contact Author)

Campbell Law School ( email )

225 Hillborough Street
Raleigh, NC 27603
United States

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