First principles
| Latin | prima principia; dignitates |
|---|---|
| Locus in Aquinas | Summa theologiae I–II, q. 94, a. 2; I, q. 79, a. 12 |
| Branch | Philosophy of knowledge |
| Controlling authority | Dei Filius; Humani Generis; Catechism 1954–1960; Thomistic synthesis |
| Doctrinal standing | The natural knowability of God and of the moral law is doctrine; the scholastic table of first principles is theology and philosophy |
| School | Thomism |
First principles are, in Thomism, the indemonstrable starting-points of speculative and practical reason, known by the natural light of the intellect and not assembled from a prior proof.[1]
What cannot be proved because it is first
Demonstration has to stop. If every proposition required a prior proof, science would never begin. Aquinas therefore assigns to the intellect a habit of first principles, sometimes called understanding, by which it sees self-evident truths once the terms are known. In speculative reason the first among these is the principle of non-contradiction, based on being and not-being: the same cannot be affirmed and denied at once. Other axioms, such as that the whole is greater than its part, are self-evident to all whose terms are common.[1]
Self-evidence is twofold. A proposition may be evident in itself because the predicate is included in the subject, yet not evident to us if we do not know the terms. 'An angel is not circumscriptively in a place' is of that kind. First principles in the strict sense are those evident to all, not a secret list for the initiated. They are not innate pictures. They are elicited when experience supplies the terms and the light of the agent intellect actualizes the intellect's natural aptitude.
Speculative and practical orders
Summa theologiae I–II, question 94, article 2, parallels the two orders. As being is first in apprehension simply, so good is first in the apprehension of practical reason, because every agent acts for an end under the aspect of good. The first precept of law is that good is to be done and pursued and evil avoided. Upon this are based the precepts that follow the order of natural inclinations: preservation of life, the union of male and female and the education of offspring, and the goods of reason, such as knowing the truth about God and living in society.[1]
Question 79, article 12, treats synderesis as the habit of these practical first principles, not as a power distinct from intellect. Conscience is the act of applying them. Catechism 1954–1960 receives the natural law as man's participation in the eternal law, present in the heart and established by reason, without adopting every scholastic name. Veritatis Splendor later insists that there are truths about the good that no consensus can repeal.[2][3]
Not erased, yet able to be obscured in application
The same question 94, article 6, holds that the most general precepts cannot be blotted from the heart as such. They can fail in a particular action when passion hinders application. Secondary precepts, which are like close conclusions, can be obscured by vicious custom, as Paul describes in Romans 1. Humani Generis defends the mind's capacity for these metaphysical and moral principles against philosophies that treat them as linguistic habits or as obsolete Greek accidents.[4]
Dei Filius had already taught that God, the beginning and end of all things, can be known with certainty from created things by the natural light of reason. First principles are the interior side of that doctrine. They do not replace revelation. They make it possible to receive revelation as true rather than as noise, and to recognize the moral law as law rather than as tribal taste.[5]
School table and Catholic confession
The Church does not publish a numbered syllabus of every scholastic axiom. She does bind the faithful to the knowability of truth, the natural law, and the distinction of speculative and moral reason from mere appetite. Thomism's table of first principles is a privileged map of that confession. Other Catholic philosophies may describe the same starting-points with different technicalities if they do not dissolve them into feeling or into a will that creates the true.[6]
Some things are obvious to an honest mind; no one is excused from the gravest moral truths; and argument has to begin somewhere. The Latin dignitates is school vocabulary. Used well, the doctrine of first principles protects both humility and courage: humility, because the light is not invented; courage, because the obvious need not be proved before injustice may be condemned or the Creator confessed.
References
- Back to citation occurrence 1.0 Back to citation occurrence 1.1 Back to citation occurrence 1.2 Thomas Aquinas, Summa theologiae I–II, question 94, article 2 — Primary statement of the first precepts of natural law and of the first indemonstrable principles of speculative and practical reason.
- Back to citation Thomas Aquinas, Summa theologiae I, question 79 — Primary treatment of the intellectual powers, including the possible intellect, the agent intellect as a power in the soul, speculative and practical intellect, and synderesis.
- Back to citation Catechism of the Catholic Church, 1949–1986 — Authoritative teaching on eternal, natural, revealed, and human law, their order, and the New Law as the grace of the Holy Spirit in Christ.
- Back to citation Pius XII, Humani Generis — Encyclical defending the knowability of metaphysical principles, the value of scholastic theology, and the distinction of the natural and supernatural orders.
- Back to citation First Vatican Council, Dei Filius — Dogmatic constitution on God the Creator, the natural knowability of God, the distinction and harmony of natural and supernatural orders, and the gratuity of revelation.
- Back to citation John Paul II, Veritatis Splendor — Encyclical on the moral law, the natural law, virtue, and the relation of human freedom to eternal and divine law without reducing morality to mere consensus.