Summa contra Cartesians

I’m currently doing some research for a paper on the anthropological implications of Chalcedonian Christology. My working hypothesis is that Christian theology has often insufficiently applied the person-nature distinction (so vital to the church’s Trinitarian and Christological formulae) to the topic of theological anthropology. So, for example, while Chalcedon understands the soul as a part of human nature in which a person subsists (Christ’s human nature consisted of a “rational soul and body”), many Christian theologians continue to articulate an understanding of human personhood that equates “soul” with “person.”  On such a Cartesian understanding, the person “just is” the soul.  But Chalcedonian Christology seems to demand a distinction between person and soul in order to avoid the error of Apollinarianism.  The person of the Son assumed a human nature that was already equipped, so to speak, with a soul, no less than a body.  So the person must be distinguished from the soul, at least in the case of Christ.  I don’t have space to defend it here, but a strong case can be made that the next ecumenical council, Constantinople II, implies that the same is true for all human persons.

In any event, this Cartesian dualism isn’t the only kind of substance dualism on offer in the Christian tradition.  Thomas Aquinas, for instance, articulated a kind of hylomorphic dualism that equated the person neither with the soul nor the body.  Instead, on Thomas’ scheme, the soul is the substantial form of the material body that gives to it its rational configuration. The person is the individual thing (suppostium) that exists in and through the soul and the body as constitutive parts of human nature.  I have a lot more to read in Thomas (as well as in the secondary literature on him), but the following discussion from the Summa Theologiae (1.75.4) should suffice to demonstrate that Thomas clearly distinguished the person and the soul.  In response to the question, “Is the soul man?” Thomas cites Augustine:

On the contrary, Augustine (De Civ. Dei xix, 3) commends Varro as holding “that man is not a mere soul, nor a mere body; but both soul and body.”

Thomas argues that the soul cannot be equated with “man,” conceived of either as a species or as an individual. Instead, Thomas maintains that the soul is a part of man along with the body.  He concludes:

Not every particular substance is a hypostasis or a person, but that which has the complete nature of its species. Hence a hand, or a foot, is not called a hypostasis, or a person; nor, likewise, is the soul alone so called, since it is a part of the human species.

So the soul is a substance, distinct from the body, but it is not a subsistence; it is not a person.  A person has the “complete nature of its species,” which, in the case of a human being, ordinarily includes (bracketing out the question of the intermediate state) a body and a soul.  In sum, Thomas maintains the person-nature distinction even outside of its normal Trinitarian-Christological context and applies it consistently to ordinary human persons as well.

5 thoughts on “Summa contra Cartesians

    • Indeed. Very helpful. But there’s still some work to be done on developing what we might call a three-part anthropology to go along with Crisp’s three-part Christology: a human person is a thing conceptually distinct from a body and a soul. The person is the individual who subsists in and through the body-soul complex, or something like that.

  1. Here might be a different way of looking at it Luke…

    A nature is a set of properties. A human nature is a set of those specific properties constitutive of humanity (e.g. embodiment, intellectual properties, emotional properties, volitional properties, etc.)

    Should we say one’s soul is part of “one’s nature”? It depends on what you mean by “soul”? I would say a soul, as it is used today, is an instantiation of a nature, not a part of a nature. It is concretizing the abstract properties of a nature into an individual, a self.

    I realize “a soul” is the way Chalcedonians have historically talked about the immaterial aspects of Jesus’ full human nature. But it would be anachronistic to say the Fathers were working with a Cartesian “soul” (i.e. a fully personal immaterial individual) in their Christology at Chalcedon. If they were, this human soul would have pressed them quite flatly into Nestorianism. I’ve understood the Fathers to mean simply by soul– those immaterial aspects of Jesus’ human nature. Apollinarius’ error was supposing the assumption of a body is sufficient to characterize Christ’s assumption of human nature. There are immaterial aspects to our nature which the Fathers called “a soul,” and in our ontology might be more precisely said to be those immaterial properties constitutive of humanity (e.g. intellectual properties, emotional properties, volitional properties, etc.) –since a nature is a set of properties. And of course this picks out something very different ontologically than a Cartesian soul.

    If this is right, the reason there is so much disconnect between Chalcedonian anthropology and contemporary biblical anthropology in this case is because of historical equivocations, not theological inconsistencies.

    I’m not a theologian, and I realize there are non-realists that would be uncomfortable with my categories, but I still have a hunch that the biggest disconnect that you’re sensing is actually definitional.

    • Anthony,
      You make some helpful points here. I didn’t mean to suggest that Chalcedonians and Cartesians are operating with the same understanding of “soul.” But in a sense I think this is precisely where the debate lies. I think that the Council of Chalcedon and its progeny were operating with a different understanding of human nature than what you have articulated here. In a more Thomist understanding, a human nature is definitionally not merely a set of abstract properties constitutive of humanity (this is Thomas’ secondary substance) but is also the concrete instantiation of those properties in a particular individual (Thomas’ primary substance). In this “concrete human nature” view (as opposed to an “abstract human nature” view), the soul is not merely the personal instantiation of a set of abstract properties but is itself a concrete substance that comprises part of a concrete human nature (Note that this isn’t anti-realist; it’s Aristotelian. The form of humanity is present in the concrete instantiation). The problem with Cartesianism is that it loses these distinctions (person/nature=soul+body, primary/secondary substance), and in losing these distinctions, surrenders several advantages that they bring. I want to explore these more in the paper. Thanks for engaging with this post and offering some helpful clarifications.

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