Plurality of forms
| Latin | Pluralitas formarum substantialium |
|---|---|
| Treatise | Opposed in Summa theologiae I, question 76, articles 3–4 |
| Controlling authority | Council of Vienne; Catechism 365 |
| Doctrinal standing | The rational soul as substantial form of the body is defined; plurality of substantial forms in man is a rejected school thesis |
| School | Thomism |
| Branch | Natural philosophy |
Plurality of forms is the scholastic thesis, opposed by Thomas Aquinas, that a corporeal substance, especially man, has more than one substantial form, so that corporeity, vegetative life, and sensation would be given by forms other than the intellective soul.
What the thesis claims
Plurality of substantial forms was a common Franciscan and eclectic position in the thirteenth century. It held that a man is a body by one form, alive by another, animal by another, and rational by yet another, or at least that a form of corporeity remains under the intellective soul. The 1913 Catholic Encyclopedia article on form records the general scholastic distinction of substantial and accidental form; the article on Thomism records that Kilwardby and Oxford doctors attacked Thomas's unicity.[1][2]
The motive was often pious. Opponents feared that if the intellective soul were the only substantial form, a corpse would not be the same body, Christ's body in the tomb would be problematic, and the remaining Eucharistic accidents would be unintelligible. The thesis is a school answer to those fears. It is not a council.
Aquinas's rejection
Summa theologiae I, question 76, article 3, asks whether besides the intellectual soul there are in man other souls essentially different. Article 4 asks whether there is any other substantial form. Aquinas answers no. One thing has one substantial being, and one substantial being is from one substantial form. A substantial form gives being simply. A second substantial form would make a second substance, or would be only accidental. The intellective soul contains the lower grades virtually, as the pentagon contains the triangle.[3]
Death is the loss of this one form. The corpse is not the man. It is the remains, with accidental dispositions that make it apt to be called the same body analogically and to be raised. That analogical identity, not a leftover corporeity-form, is the Thomist reply to the tomb and the cemetery.
Vienne and the remaining question
The Council of Vienne defined that the rational soul is of itself and essentially the form of the human body, against Peter John Olivi. The Catechism of the Catholic Church, 365, repeats the definition. Thomists read this as closing plurality in man. Other Catholic historians note that the definition targets a denial that the intellective soul is the form, and may not have intended to settle every technical dispute about a form of corporeity.[4][5]
The encyclopedia presents unicity as the Thomistic synthesis under the defined unity. It does not pretend that every medieval Franciscan who held plurality was a heretic. After Vienne, a Catholic may not deny that the rational soul is the substantial form of the body. He may still ask how the definition maps onto later scholastic vocabulary. That asking is theology, not a reopening of the definition.
Why the fight still instructs
Plurality and unicity are two ways of protecting the same Catholic facts: the body is real, the soul is spiritual, the man is one, the dead await resurrection. Each school accused the other of losing one of those facts. The Thomist accusation is that plurality makes the man a committee of forms. The plurality accusation is that unicity makes the corpse a heap and the Incarnation a riddle.
The correctoria of the 1270s turned that argument into pamphlets. The living question for the reader is the unity of the person, not the score of a medieval faculty fight.
References
- Back to citation Catholic Encyclopedia (1913), Thomism — Public-domain history of Thomist principles, the correctoria after 1277, the unicity of substantial form, and the Leonine restoration.
- Back to citation Catholic Encyclopedia (1913), Form — Public-domain account of substantial and accidental form in scholastic philosophy.
- Back to citation Thomas Aquinas, Summa theologiae I, question 76 — Primary hylomorphic anthropology: the intellective soul as form of the body and the rejection of a plurality of substantial forms in man.
- Back to citation Council of Vienne, Fidei catholicae — Conciliar definition that the rational soul is of itself and essentially the form of the human body, against any denial of that substantial unity.
- Back to citation Catechism of the Catholic Church, 355–368 — Authoritative anthropology of the human person as a unity of body and soul, the soul as form of the body, and the soul's immediate creation and immortality.