Reason (Lat. ratio, intellectus) is the essential characteristic of the human person. It denotes the faculty for cognizing the truth of things and for grasping in insights what something is. Rational nature distinguishes the human being from all other bodily living beings.
Reason and Personhood
Already Boethius defines the person as naturae rationalis individua substantia — the indivisible substance of a rational nature. Reason thus belongs to the constitutive nature of the human being, and not merely to its actual exercise. A human being is endowed with reason even when he does not (yet) actually exercise it — as in the case of the embryo or the human being with dementia.
Reason as Person-Behavior
Within the second dimension of personhood, reason belongs to person-behavior: to the rationally-affectively conscious and volitionally free being of the person (Bexten 2017, pp. 259 ff.). Reason is therefore not a criterion for personhood but its expression. This stands in contrast to the empirical-functionalist concept of person, which makes the use of reason a condition of personhood.
Reason and Freedom
Reason and freedom condition one another: only one who cognizes can choose freely, and only one who is free can follow the truth that has been cognized. The actus humanus — the conscious, free action — presupposes both. Thomas Aquinas emphasizes that the human being participates in divine providence precisely through reason.
Demarcation
Max Scheler warns against narrowing the image of the human being to reason alone. The human being is not merely animal rationale, but essentially also a loving and self-transcending person. Peter Wust speaks of the “taking of measure by the spirit from things” and thereby connects reason with humble receiving.
Ontological classification: Reason (rationality) is (according to the ontology) a subclass of the essential characteristic of the person. It belongs to rational nature.
Sources: Generated by querying the Personhood ontology.
Further sources:
- Boethius: Contra Eutychen et Nestorium, cap. 3. (the person as naturae rationalis individua substantia)
- Aquinas: Summa Theologiae, I, q. 79, aa. 1–4 (intellectus and ratio as faculties of the rational soul)
- Scheler, Max (1913/1916): Der Formalismus in der Ethik und die materiale Wertethik. Halle: Niemeyer. (German) (warning against narrowing the image of the human being to reason)