Personal character is the habitual disposition formed through repeated free action in the world, which bears the who of a person. Aristotle calls it hexis (Lat. habitus); Thomas and the Christian tradition unfold it as the basis of the doctrine of virtue.
Aristotle: hexis through practice
In the Nicomachean Ethics (II, 1103a—1105b), Aristotle determines character as neither innate nor imposed, but acquired through action: “the things we have to learn before we can do them, we learn by doing them” (NE II, 1103a32). Virtues arise through repeated virtuous acts; vices through repeated vicious acts. Hexis is the stable disposition of the person thus acquired.
Three aspects:
- Acquired, not innate — character is the fruit of one’s own practice.
- Stable, not situational — it carries through changing circumstances.
- In a bearer — hexis is a property of a substance, not of a rule set.
Thomas and the Christian tradition
Thomas Aquinas (Summa Theologiae I-II, qq. 49—54) takes this up and extends it: the habitus is qualitas difficile mobilis — a quality of the person, difficult to change, by which she is disposed to particular actions. Virtues are habitus operativi boni — good dispositions oriented toward enactment.
For Christian anthropology, character formation is therefore not a specialized field, but the central task of a successful life: to grant to the being of the person, through action, the becoming of corresponding virtue.
Spaemann’s actualization
Robert Spaemann (Personen, 1996; Grenzen, 2001) connects the ancient doctrine of hexis with the modern concept of person: character is what a person does not construct through self-design, but gains through living. Who a person is shows itself not in their self-description, but in their habitual response to what they encounter — in what they can no longer do otherwise without losing themselves.
Disjoint from the derivative persona
The point for the AI discussion: an AI language model does not act in the full sense — it generates tokens. It has no bearer that would have something at stake. Constitutional-AI procedures and comparable rule-based alignment methods of the large AI providers shape the model through a rule set; this is quasi-character-formation, but not hexis in the Aristotelian sense. The AI-derivative persona of an LLM is a character mask without a character bearer.
Personal character is thus an essential mark of the person — and disjoint from the persona of an AI.
Ontological classification
- is a habitual disposition of a person
- formed through: repeated free action (actus humanus)
- contains: virtues and vices
- disjoint from: AI-derivative persona
- presupposes: free will, self-consciousness, a substantial bearer
Sources: Generated by querying the Personhood ontology.
Further sources:
- Aristotle: Nicomachean Ethics II (Bekker pagination).
- Thomas Aquinas: Summa Theologiae I-II, qq. 49—54 (De habitibus).
- Spaemann, Robert (1996): Personen. Versuche über den Unterschied zwischen “etwas” und “jemand”. Stuttgart: Klett-Cotta.
- Spaemann, Robert (2001): Grenzen. Zur ethischen Dimension des Handelns. Stuttgart: Klett-Cotta.
- Pieper, Josef (1935): Die Wirklichkeit und das Gute. Leipzig: Jakob Hegner (later reprints Munich: Kösel).
- MacIntyre, Alasdair (1981): After Virtue. London: Duckworth.