Abstract
Wood’s chapter contrasts Aquinas and Buridan on the question of the relationships between souls and their powers. Both thinkers considered the question of whether the soul’s powers are distinct from the soul itself, and both gave an affirmative answer, but differed in that Aquinas insisted on a real distinction whereas Buridan was satisfied with a merely nominal or conceptual distinction, at least as far as principal powers are concerned; Buridan also distinguished instrumental powers, which he took to be really distinct from the substance of the soul. The chapter argues that anyone interested in allowing Aristotelian souls and psychological powers into their ontology at all—as both Aquinas and Buridan were—should draw a real, rather than merely nominal or conceptual, distinction between souls and powers (and between the powers themselves). Because Aquinas did so, and Buridan did not, Wood concludes that Aquinas has the better side of this debate.
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Notes
- 1.
I restrict my claim here to material substantial forms simply because if Aquinas is correct that God is a substantial form (cf. Aquinas, ST 1a.3.2), then I want to leave open the possibility that we have reasons for including him in our ontology unrelated to the sorts of unifying role that concern me here.
- 2.
I say “many” other medieval Aristotelians rather than “all” in deference to the great diversity of scholastic opinions concerning substantial forms. Perhaps some had good reasons for invoking substantial forms that had nothing to do with their unifying roles. I’m not sure what these reasons would be, though.
- 3.
This might not seem perfectly obvious. The reason is that if we speak of psychological powers at all nowadays, we probably mean “the sorts of powers that psychologists talk about.” In an Aristotelian context, however, I take “powers of the soul” to mean just “the abilities/capacities/faculties that the soul gives rise to,” which is why having such powers without souls isn’t an option.
- 4.
- 5.
As Descartes puts it in the Fifth Set of Replies, “I consider the mind not as part of the soul but as the thinking soul in its entirety” (1984, 246; AT 7:356).
- 6.
In my estimation Buridan’s view on the relationship between souls and their powers also faces serious difficulties reconciling the immateriality of human intellective powers with the apparent materiality of many of our other vital capacities. But I’ll omit any discussion of these issues in what follows.
- 7.
See Aquinas, ST 1a.76.3–4 and Buridan, QDA II, q. 4; III, q. 17.
- 8.
See Pasnau (2011, Chap. 16) for more on holenmerism in More and others.
- 9.
QDA II, q. 1, n. 11: “the principal operations of animate beings, such as nutrition, sensation and so on are reduced to the soul as their principal source.” Cf. Aquinas, ST 1a.75.1: “the soul is defined as the first principle of life in those things in our world which live ... [and] life is shown principally by two activities: knowledge and movement.”
- 10.
See De principiis naturae 2 on the distinction between necessary and non-necessary accidents.
- 11.
See Park (1980) for more on Albert’s view.
- 12.
See Arlig (2011) for more on the relationship between Boethius’ virtual parts and their wholes.
- 13.
Strictly speaking, for Aquinas, it is the composite of soul and body that is the subject of all psychological powers other than intellect and will (see ST 1a.77.8).
- 14.
Ockham argues in Rep. 2.20 that intellect and will are identical to one another and in Rep. 3.4 that sensitive powers are identical to the sensitive soul and to one another, although he also holds that the intellective and sensitive souls are two really distinct substantial forms (see Quodlibet 2.10). In Rep. 2.20 Ockham explains that sometimes distinct operations require distinct principles, and sometimes not; experience and what is evident to reason must be our guide here. In the case of the intellect and will, there is no evident reason for thinking their operations proceed from distinct powers (ed. Gál and Wood 1981, 444). See King (2008, 269–271) and Pasnau (2002, 157–158).
- 15.
“Ad illas auctoritates quae dicunt quod anima ebullit potentias, et potentiae erumpunt ab essentia animae et fluunt et sunt passiones animae ... dico quod potentia potest accipi pro omni eo quod ponitur in descriptione quid nominis potentiae vel pro illo quod denominatur. Primo modo verae sunt auctoritates illae, quia potentia intellectiva sic accepta non tantum significat essentiam animae sed connotat actum intelligendi. Et eodem modo voluntas. Nunc autem anima ebullit actum, et actus fluit ab anima et erumpit sicut effectus a sua causa partiali et principali. Et sic intelligatur auctoritates omnes. ... Et eodem modo metaphorice potest causa ebullire effectum. Sed accipiendo potentiam secundo modo, sic non est verum, nec sic intelligunt auctoritates in illis locutionibus metaphoricis” (Gál and Wood 1981, 437–438).
- 16.
“… if a power were an accident of the soul, then the soul would be in potency to it, since a subject is in potency to all its accidents. So, either it would be in potency to that potency by itself, and then by parity of reasoning we could have said this from the beginning, or else it would be in potency to that potency by some other potency, and then we’d face an infinite regress.” I trace this style of argument to Henry of Ghent’s Quodlibet 3.14, although I also find versions of it in Scotus, Ockham, Richard of Middleton and Peter John Olivi. Thomas of Sutton in Quodlibet 3.7 and Godfrey of Fontaines in Quaestio disputata 12 both respond to it at length. See my 2011 work (605–610) for references.
- 17.
Buridan doesn’t raise this objection himself, as far as I know, but some later identity theorists like Olivi, Gregory of Rimini and Marsilius of Inghen do (see Olivi, II. Sent. 54; Marsilius, Quaestiones super quattuor libros Sententiarum 1.7.3 and Gregory, Lectura super primum et secundum Sententiarum 2.16/17.3).
- 18.
It’s worth noting that later Baroque scholastics, while adopting the Thomistic distinction thesis by and large, think all of these concerns I’ve just mentioned are well worth worrying about. See for instance the Coimbran De anima commentary 2.3.3–4, Franciscus Toletus’s De anima commentary 2.4.10 and Francisco Suarez’s Metaphysical Disputations 18.2–3. See also Des Chene (1996, 158–167; 2000, 143–152) for useful discussions of seventeenth century debates on souls and their powers.
- 19.
In Quaes. DA 12 sc 1 Aquinas explains that since posse is related to agere just as essentia is related to esse, it is equally true that agere is related to esse just as any potentia is related to its corresponding essentia. But since only in God are agere and esse identical, so too any creaturely powers are distinct from the essence of that whose powers they are. So psychological powers are distinct from the soul’s essence. See Aquinas, 1SN 3.4.2; ST 1a.77.1 and De spirit. creat 11 for similar reasoning, and Pasnau (2002, 152–153) for discussion.
- 20.
See QMETA VIII, q. 4 for his arguments that essence and existence are identical in creatures.
- 21.
“Praeterea, cum perfectio et perfectibilia sint proportionata, oportet quod perfectibilia diversarum proportionum recipiant diversas perfectiones. Organa autem corporis animati diversa sunt diversarum proportionum in commixtione. Ergo diversimode perficiuntur ab anima. Non autem quantum ad esse, quia anima, cum sit forma substantialis, dat unum esse toti corpori. Ergo oportet quod diversimode perficiantur quantum ad perfectiones consequentes esse, secundum quas habent diversas operationes. Has autem perfectiones, quae sunt principia operationum animae, vocamus potentias. Ergo oportet potentias animae diversas esse ab essentia, utpote emanantes ab ipsa.”
- 22.
One odd consequence of Buridan’s view that souls, together with their principal powers, are spread uniformly throughout the body of any living thing emerges in QDA II, q. 7. He argues there that because the soul (together with all of its principal powers) is present in each and every part of a living thing’s body, each and every quantitative part of an organism is itself an organism of the same type. For instance, every quantitative bit of a horse is itself a horse. Properly speaking, he explains, “horse” turns out to be a mass-noun like “water” or “air” rather than the count-noun we generally treat it to be. Now, Aquinas drew explicitly on his thesis that the soul is really distinct from its powers in order to avoid having to say that every quantitative bit of an organism is itself an organism of the same type (ST 1a.76.8 ad 3; De spirit. creat 4). If he was correct that his distinction thesis yields this result, then one might argue that the odd consequence of Buridan’s identity thesis—having to allow that every quantitative bit of a horse is a horse—gives us a further reason for preferring Aquinas’ position. See Calvin Normore’s contribution to this volume for more on this view of Buridan’s.
- 23.
See Pasnau (2004, 39–44; 2011, Chap. 24) for discussion.
- 24.
See also ST 1a.76.8.
- 25.
See for instance Klima (2005) on how Buridan supports a robust scientific essentialism without any shared forms or essences, and Lagerlund (2012, 474–479) on how Buridan accounts for the diachronic unity of material substances without appeal to their substantial forms. See also Pasnau (2011, Chap. 29).
- 26.
Pasnau (2012, 488) discusses one metaphysical role that Buridan appears still to have substantial forms playing in QDA III, q. 11: accounting for the difference between accidental and substantial change. I’m not clear on how this argument relates to his argument in QPHYS I, q. 10 that the diachronic unity of the river Seine can be explained simply by appeal the continuity of its water-parts. A number of scholars have recently argued that physical roles like the ones I mention here became increasingly prominent in later medieval discussions of substantial forms. See Pasnau (2004, 2011, Chap. 24), Hattab (2009), Hill (2007, 18), Emerton (1984, 48–75) and Des Chene (1996, 64–75). For instance, they are central to Suarez’ lengthy argumentation in favor of substantial forms in Metaphysical Disputations 15. See Hattab (2009, Chap. 3; 2012). See Shields (2012). Descartes, of course, denies both that substantial forms are capable of explaining such natural phenomena as Buridan cites and that they are needed to do so; see his January 1642 letter to Regius (Descartes 1991, 205–9; AT 3:491–509).
- 27.
Kronen (1991) emphasizes the importance of such unifying roles in Suarez’ argumentation for substantial forms.
- 28.
Zupko (2003, 171–175) has called this Buridan’s “homogeneity principle.”
- 29.
Cf. Nagel (1961).
- 30.
See, for example, Wimsatt (1974). Bechtel and Richardson (2010) quote from the latter article (Wimsatt 1974, 671): “At least in biology, most scientists see their work as explaining types of phenomena by discovering mechanisms, rather than explaining theories by deriving them from or reducing them to other theories, and this is seen by them as reduction, or as integrally tied to it.”
- 31.
Machamer et al. (2000, 1–25) provides a useful overview of this literature.
- 32.
“Much has already been said about the soul ... [and] there remains now only to speak about the body. Now since the consideration of the body is double, namely with respect to it as a whole and to the members which constitute the composite whole, and since, as we have often said, we only know the whole when we know whence, what sort, and how much something is, we ought to put the investigation on the parts and members of animals ahead of the one on the body of the animal as a whole” (trans. Kitchell and Resnick 1999, 45–46). And ibid. 1.1.2: “By way of beginning, let us state that a member of an animal is that into which the body is divided, out of which it is made whole and composed...” (trans. Kitchell and Resnick 1999, 48).
- 33.
Trans. Kitchell and Resnick (1999, 67).
- 34.
Elsewhere in the De animalibus, for instance, but also in his Questions Concerning Aristotle’s On Animals and De nutrimento et nutribili.
- 35.
See Aquinas, Sent. DA 2.2.239 (discussing Aristotle’s eye/soul analogy) and ibid. 2.24.555: “the first sensory capacity—i.e., the first organ of sense—is that in which there is a power of this sort (a power, namely, that is capable of taking on species without matter). Therefore the sensory organ, along with the power itself (for example, the eye), are the same in subject, but they are different in being, because the power differs from the organ in ratio. For the power is as if the organ’s form, as was established earlier [i.e., in the eye/soul analogy].”
- 36.
Bechtel and Abrahamsen (2005, 423) for instance, characterize them this way: “A mechanism is a structure performing a function in virtue of its component parts, component operations, and their organization. The orchestrated functioning of the mechanism is responsible for one or more phenomena.”
- 37.
Buridan writes that “natural heat and several dispositions of the soul or the body cooperate in nutrition as instrumental agents that the soul uses for effecting nutrition as the blacksmith uses fire and hammer. ... Therefore, these dispositions, which the soul uses as instruments for nutrition, are instrumental nutritive powers, and they differ from the nutritive soul” (QDA II, q. 5, n. 20). Elsewhere he characterizes the structures that incline us to speak of a living thing’s body as “organic and heterogeneous,” with “dissimilar quantitative parts,” as “accidental dispositions added to the substance of the animal [itself]” (QDA II, q. 7, n. 25).
- 38.
Descartes complains that “substantial forms ... were introduced by philosophers to account for the proper actions of natural things, of which they were supposed to be the principles and bases ... But no natural action at all can be explained by these substantial forms, since their defenders admit that they are occult and that they do not understand them themselves. If they say that some action proceeds from a substantial form, it is as if they said that it proceeds from something they do not understand; which explains nothing. So these forms are not to be introduced to explain the causes of natural actions” (Descartes 1991, 208–209; AT 3:506). Arnauld seconds this assessment, writing that “the word ‘faculty’ is used wrongly when ... one claims to have given an explanation of an effect which is unknown, or known very confusedly, by using the general term ‘faculty’ to describe its cause, as when one says that the magnet attracts iron because it has this faculty, or that fire changes certain bodies into glass through a natural faculty. For the abuse of the word in those cases consists principally in this: before knowing what is involved in iron being attracted to a magnet, or what is involved in ashes being changed into glass by a fire, one is satisfied with saying that the magnet and the fire each have these faculties. But if, after having explain, as Descartes does, what vitrification is and what fire contributes to it, and what the attraction of iron by a magnet is and what the magnet contributes to it, one then asked anew how it comes about that fire has this violent motion which causes certain bodies to change into glass, and how it comes about that the magnet has screw-shaped power, then it would be perfectly all right to reply that it is because such is the nature of the bodies that we call fire and magnets” (Arnauld 1990, 153–54).
- 39.
Bibliography
Primary
Albert the Great. (1999). In I. Resnick & K. Kitchell (Eds. and Trans.), De animalibus. Baltimore: Johns Hopkins University Press.
Arnauld, A. (1990). In S. Gaukroger (Trans.), On true and false ideas. Manchester: Manchester University Press.
Descartes, R. (1984). Fifth set of replies. In J. Cottingham, R. Stoothoff, & D. Murdoch (Eds.), The philosophical writings of descartes (Vol. 2). Cambridge: Cambridge University Press.
Descartes, R. (1991). Letter to Regius, January 1642. In J. Cottingham, R. Stoothoff, D. Murdoch, & A. Kenny (Eds.), The philosophical writings of descartes (Vol. 3). Cambridge: Cambridge University Press.
Melancthon, P. (1834–1860). Liber de anima. In C. G. Bretschneider & H. E. Bindseil (Eds.), Philippi Melanchthonis Opera quae supersunt omnia. Halle: Halis Saxonum.
Secondary
Arlig, A. (2011). Medieval mereology. In E. Zalta (Ed.), The Stanford encyclopedia of philosophy. http://plato.stanford.edu/entries/mereology-medieval
Armstrong, D. (1999). The mind-body problem: An opinionated introduction. Boulder: Westview.
Baker, M., & Goetz, S. (2011). The soul hypothesis: Investigations into the existence of the soul. London: Continuum.
Bechtel, W., & Abrahamsen, A. (2005). Explanation: A mechanist alternative. Studies in the History and Philosophy of the Biological and Biomedical Sciences, 36, 421–441.
Bechtel, W., & Richardson, R. C. (2010). Discovering complexity: Decomposition and localization as strategies in scientific research. Cambridge: MIT Press.
Cartwright, N. (1994). Nature’s capacities and their measurement. Oxford: Oxford University Press.
Cummins, R. (1975). Functional analysis. The Journal of Philosophy, 72(20), 741–765.
Des Chene, D. (1996). Physiologia: Natural philosophy in Late Aristotelian and Cartesian thought. Ithaca: Cornell University Press.
Des Chene, D. (2000). Life’s form: Late Aristotelian conceptions of the soul. Ithaca: Cornell University Press.
Emerton, N. (1984). The scientific reinterpretation of form. Ithaca: Cornell University Press.
Fine, K. (1999). Things and their parts. Midwest Studies in Philosophy, 23, 61–74.
Fine, K. (2010). Towards a theory of part. The Journal of Philosophy, 107, 559–589.
Groff, R., & Greco, J. (Eds.). (2013). Powers and capacities in philosophy: The New Aristotelianism. Oxford: Oxford University Press.
Handfield, T. (Ed.). (2009). Dispositions and causes. Oxford: Oxford University Press.
Hattab, H. (2009). Descartes on forms and mechanisms. Cambridge: Cambridge University Press.
Hattab, H. (2012). Suarez’s last stand for the substantial form. In B. Hill & H. Lagerlund (Eds.), The philosophy of Francisco Suarez (pp. 101–120). Oxford: Oxford University Press.
Hill, B. (2007). Substantial forms and the rise of modern science. The St. Anselm Journal, 5(1), 1–23.
Jacobs, J. (Ed.). (2017). Putting powers to work: Causal powers in contemporary metaphysics. Oxford: Oxford University Press.
Johnston, M. (2006). Hylomorphism. The Journal of Philosophy, 103, 652–698.
King, P. (2008). The inner cathedral: Mental architecture in high scholasticism. Vivarium, 46, 253–274.
Kistler, M., & Gnassounou, B. (Eds.). (2007). Dispositions and causal powers. Aldershot: Ashgate.
Klima, G. (2005). The essentialist nominalism of John Buridan. The Review of Metaphysics, 58(4), 739–754.
Koslicki, K. (2008). The structure of objects (pp. 229–256). Oxford: Oxford University Press.
Kronen, B. (1991). The importance of the concept of substantial unity in Suarez’ argument for hylomorphism. American Catholic Philosophical Quarterly, 65, 335–360.
Lagerlund, H. (2012). Material substance. In J. Marenbon (Ed.), The Oxford handbook of medieval philosophy (pp. 468–485). Oxford: Oxford University Press.
Machamer, P., Darden, L., & Craver, C. (2000). Thinking about mechanisms. Philosophy of Science, 67, 1–25.
Marmadoro, A. (Ed.). (2010). The metaphysics of powers: Their grounding and manifestations. London: Routledge.
Nagel, E. (1961). The structure of science. New York: Harcourt, Brace and World.
Oderberg, D. (2007). Real essentialism. London: Routledge.
Park, K. (1980). Albert’s influence on late medieval psychology. In J. A. Weisheipl (Ed.), Albertus magnus and the sciences: Commemorative essays 1980 (pp. 501–536). Toronto: Pontifical Institute of Mediaeval Studies.
Park, K. (1991). The organic soul. In C. Schmitt, Q. Skinner, E. Kessler, & J. Kraye (Eds.), The Cambridge history of renaissance philosophy (pp. 464–484). Cambridge: Cambridge University Press.
Pasnau, R. (2002). Thomas aquinas on human nature. Cambridge: Cambridge University Press.
Pasnau, R. (2004). Form, substance and mechanism. The Philosophical Review, 113(1), 31–88.
Pasnau, R. (2011). Metaphysical themes: 1274–1671. Oxford: Oxford University Press.
Pasnau, R. (2012). Mind and hylomorphism. In J. Marenbon (Ed.), The Oxford handbook of medieval philosophy in the Oxford handbook of medieval philosophy (pp. 486–504). Oxford: Oxford University Press.
Salmon, W. (1984). Scientific explanation and the causal structure of the world. Princeton: Princeton University Press.
Shields, C. (2012). The reality of substantial form: Suarez, metaphysical disputations XV. In D. Schwartz (Ed.), Interpreting Suarez: Critical essays (pp. 39–61). Cambridge: Cambridge University Press.
William of Ockham. (1981). Reportatio 2.20 in Opera theologica 5:440. In G. Gál and R. Wood (eds.), St. Bonaventure, NY: The Franciscan Institute.
Wimsatt, W. (1974). Reductive explanation: A functional account. Philosophy of Science Association, 671–710.
Zupko, J. (2003). John Buridan: Portrait of a fourteenth-century arts master. Notre Dame: University of Notre Dame Press.
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Wood, A. (2017). Aquinas vs. Buridan on the Substance and Powers of the Soul. In: Klima, G. (eds) Questions on the Soul by John Buridan and Others. Historical-Analytical Studies on Nature, Mind and Action, vol 3. Springer, Cham. https://doi.org/10.1007/978-3-319-51763-6_5
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