The book deals with the Aristotelian theories of the soul in the late 16th and early 17th century. The relevant texts are the works of the Jesuit scholastics Francesco de Toledo (Toletus), Francesco Sua/rez and Petrus Fonseca, the authors of the Coimbran commentaries of Aristotle and Roderigo de Arriaga. The subject matter is the scientia de anima, which covers not only the psychic functions as they are understood nowadays; rather, in the wake of Aristotle’s view, it meant the science of life-functions. All in all, Des Chene successfully shows that these philosophers were fully aware of the problems in Aristotle’s notion of the soul. He also shows that the questions fundamental to the Aristotelian psychology were not so much answered by Descartes and his followers as mooted.
The book divides into four main parts. The first discusses the data and presuppositions for the study of souls. The data are derived from experientia, but this does not imply that that they are derived from personal experience only. They may be a result of impersonal reports or contrived situations. Although reports of illusions are an exception to the rule that experientia records the usual course of events, they play an important role in the explanations of natural and psychic phenomena. In the commentaries on Aristotle’s Physics, monsters are mentioned in part to illustrate the notion of chance. Another difference between the result of various experientiae is the gap between the physical and psychological descriptions of sensory processes. (The divergence, we can add, may be traced back to the twofold definition of anger in De Anima I 1, 403a30-b1.) In the Jesuit commentators, the physical description entails natural ends, but the cognitive purpose of yielding true belief, which enables us to distinguish between veridical sensations and illusions, remains in the background.
The other source for the data in natural philosophy was faith. Unlike the data that arise from experientia, the data derived from faith are codified and warranted by religious authorities. Des Chene depicts carefully the stages of the response the Catholic Church gave to those who, like Pomponazzi, denied the immortality of the soul. For an accurate summary of the Church’s position, he refers us to Toletus’ list of ten points concerning the main tenets. The human soul is immortal, which means that it is incorporeal. The part of us that survives must be individual, otherwise reward and punishment in the afterlife make no sense. On the other hand, the body is not a mere instrument. Our feelings and passions, even if they are intimately tied to the body, are parts of our nature.
The second part deals with the various approaches used to interpret the Aristotelian definition of the soul. The soul is defined in terms of life. It is the form of a body that has life potentially ( De Anima II 1, 412a27-28, b5-6). The domain of life has no sharp edges: when some philosophers denied life to plants, or even to animals ( bruta), the concept of life itself was at stake. For Sua/rez, “living things are those that have the power of moving and perfecting themselves by virtue of something intrinsic ( ac perficiendi ab intrinseco habent)” ( De Anima 1c1no3, Opera 3: 468, quoted on p. 55). One criterion for having the source of movement within is immanence. When a faculty operates, its actions should remain within itself or within the substance it belongs to. Another criterion is that such actions originate from an intrinsic principle. Others cannot perform certain actions that are performed by a certain agent. Only my soul can make my body grow. But so understood, only vegetative activities can be immanent, and this is why Arriaga rejected these criteria.
On discussing the sense in which soul can be called form, the commentators were about to refuse the view attributed to Galen according to which soul is a temperament, that is an accident of the body. The theory is also well known from the Phaedo (advocated by Simmias), Aristotle’s De Anima, and the Peripatetic Dicaearchus. Arguments against the Galenic position also aim at demonstrating that the soul is substance and the form of the body. Some arguments are based on physical and metaphysical assumptions. To mention but one example, accidents can never act in their own right, only when used by a substance. The soul acts insofar as it thinks and moves the body. Furthermore, living and nonliving differ not only by one quality or quantity, but also by a bundle of properties. The collocation of the bundle can be accounted for only by positing a single unifying principle, the soul as form. Temperament does not explain the existence of higher capacities, such as reason and will, that sometimes are in conflict with other capacities in the soul. These arguments turn up again and again, long after Aristotelianism is gone.
Thus soul is a form, but the concept of form is ambiguous. The commentators distinguished forma informans and forma assistens. The former informs the matter and unites it substantially or is joined to an incomplete substance, the organic body. The latter, however, is joined to a complete substance. It operates the body like a steersman navigating his ship. The soul cannot be forma assistens because this would imply that it is either a simple substance or a composite one. If it is composite and living, then we are facing an infinite regress for to be alive the thing must possess soul. The assumption of an immaterial substance seemed also absurd (p. 78, though I do not really see why). Therefore, the soul is forma informans. This also means that the Aristotelians did their best to fend off the forma assistens, the “ghost in the machine”.
The second definition (soul is the principle of life and motion) serves as the basis from which to demonstrate the first. But the type of demonstration is a matter of dispute. As some demonstrations are from cause to effect (a priori) and others are from effect to cause (a posteriori), the question will be this: on proving the first definition from the second, does Aristotle argue from effect to cause or from cause to effect? Operations and faculties of life are related to the soul both as ends and effects to an efficient cause. Toletus ( In De Anima 2c2q3, Opera 3: 52ra) argues that the second definition is demonstrated from the first and concludes that the demonstration is a priori. Operations are thus taken as final causes, and he demonstrations based on them are a priori (see also the Coimbran commentary on De Anima 2c2q2). By contrast, Sua/rez took the operations to be the effects of the soul as efficient cause. For him, to treat them as ends is to treat the soul “in relation to existence and production” ( De Anima 1c3no2, Opera 3: 492). Essence is different from existence and defined in abstraction from existence and production. Therefore, although the proof preferred by Sua/rez is a posteriori—thus lacking the certainty of the a priori proof—it can indicate the nature and the essence of the soul.
The third part focuses on the interpretations of the powers and parts of the soul. The commentators were talking about two kinds of unity: functional unity, with the soul considered as the principle of the functions of living beings, and the unity of the soul as the form of the organic and divisible body. Divisibility of the soul was a subject of debate. Some plants and animals (e.g., worms) can be split into distinct parts that continue to live. Because the case is different in humans, can we say that human soul is indivisible? To find a response to this question, the commentators first distinguished two kinds of powers, active and passive. The active power was further divided into immanent and transeunt. The former produces in the external thing a form similar to its own, while the latter, such as knowing and loving, has no such effect. Des Chene shows (p. 121) that the Aristotelians took two object-relations (to beat a bush and to think of beating one) together. The reason is that, for them, the definition of a power does not require the actual existence of the object, only its possibility. Sua/rez posited a rank between the formal defining characters (e.g., visibility) of the objects. The order of perfection of the powers involves an hierarchy among the formal characters of their objects. Vision has the visible as its formal character, imagination, more perfect than vision, has the sensibilia, all corporeal accidents, and the intellect has all things that are intelligible, corporeal or not. Furthermore, once we find the defining formal character of the objects of a power, all characters subsumed under that character belong also to that power, though not necessarily as its primary objects. In the long run, such a notion can help us establish the unity of the human soul. On the other hand, the criteria by which powers can be distinguished are neither purely functional nor purely physical. At any rate, perceptual change takes place in the sense organ (not in the Cartesian res cogitans) or in the soul insofar as it informs the sense organ.
The last part is devoted to the unity of the soul. Here we find a version of the scala naturae. Humans differ from animals not only by possessing a spiritual power, but also by having their sensitive capacities elevated. Sua/rez ( De Anima 1c6no9, Opera 3: 504) argues that in animals the vegetative capacities have greater perfection which can only be due to the fact the animals have senses. The vegetative capacities in animals are peculiarly adapted to serve the sensitive capacities. This rule can also apply to humans (Coimbran commentaries, De Gen. et Corr. 1c4q21a2). The sensitive capacities in the human soul differ essentially from the sensitive capacities in bruta. This assumption enabled the commentators to answer the argument against the unity of the human soul which says that there is no unity in the human soul because the rational soul is immortal, but the sensitive soul is mortal. The Coimbran commentator (Emmanuel de Goes) claims that the nature of the sensitive soul is indifferent to corruptibility; it is mortal in bruta, but immortal in humans ( In De Gen. et Corr. 1c4q21a3). Thus in animals we have to distinguish functional unity from integral unity. Moreover, Arriaga’s arguments also demonstrate that the correlation between extension and materiality, or between the lack of extension and immateriality, is far from being as obvious as Descartes thought (pp. 183-186).
From the point of view of those who are engaged in ancient philosophy, the book not only shows that these texts are worth reading as interpretations of Aristotle’s theory of the soul, but also raises an important question about the meaning of “Aristotelianism”. Many of the concepts and doctrines used by the Jesuit commentators have a distinctly Neoplatonic origin. A few examples will suffice. The science of soul exceeds all other types of natural philosophy because it has a strong ethical relevance (see Toletus, In De Anima 2c1q2, Opera 3: 45ra; Sua/rez, De Anima, Prooemium, Opera 3: 464, both referred to on p. 17). This may be implicit in Aristotle, but it has been explicitly claimed by Philoponus ( in DA 25.3 ff. CAG XV). The classification of different phantasiai in Toletus ( In De Anima 3c3q8, Opera 3: 128vb; the reference is on pp. 29-30), and the related problem of the presence of such capacity in ants, bees and worms recall Philoponus ( in DA 495.10 ff. CAG XV). The view that the special organization of matter constituting the body is fit to receive the soul and not some other form (p. 90), or that each power in the soul is specially fitted to perform certain activities, comes from the Neoplatonists, though it may be rooted in the Stoa.1 The words coaptatio/aptitudo and their cognates refer to
Three minor points. I guess Sua/rez used the word species in the sense of form, thus reflecting on the intimate link between species and
The book is furnished with index and bibliography, both of the primary sources and of the secondary literature. It helps us to realize how rich the Aristotelian tradition is and reveals interesting and subtle ways to interpret the De Anima. This is also why it deserves to be read by classicists as well.
Notes
1. See R. B. Todd, ‘EPITHDEIOTHS in philosophical literature: Towards an analysis’, Acta Classica 15 (1972), 25-35.
2. As has been shown by C. H. Kahn, ‘Discovering the will. From Aristotle to Augustine’, in J. M. Dillon & A. A. Long (eds.), The Question of “Eclecticism”. Studies in Later Greek Philosophy. Berkeley/LA/London, 1988, 234-259.