Author: Leen Spruit
Part of: Suárez’s Psychology and Noetics (coord. by Anna Tropia)
Peer-Reviewed: Yes
Published: February, 14th, 2019
DOI: 10.5281/zenodo.2579091

The latest version of this entry may be cited as follows: Spruit, Leen, “Francisco Suárez, Theory of Species and Abstraction”, Encyclopedia, Mário Santiago de Carvalho, Simone Guidi (eds.), doi = “10.5281/zenodo.2579091”, URL = “”, latest revision: February, 14th, 2019.


Francisco Suárez detached himself from Thomistic cognitive psychology on several fundamental points. He relativized the distinction be­tween agent and possible intellect, assigning to the latter the principal role in the cognitive process, and regarding the former as a mere dispositional power (CdA, IX, 8). Furthermore, he explored the possibility of an immediate cognitive grasp of singu­lar entities. Intellectual abstraction concerns only the materiality of a particular thing, not its concrete existence (CdA, IX, 3-4; DM, VI, 6, n. 7; Ludwig 1929: 115 and 119). From the fact that the intellect’s first object is a sensible individual, grasped by means of an intelligible species, it does not follow that the (inner) senses and their representations have any direct influence on the production of intellectual knowledge. They merely provide the occasion for the mind to generate mental representations and cognitive acts. Thus, Suárez’s psychology borrowed not only from the nominalist tradition, but it also drew on ideas from straightforward opponents of Thomist psychology, such as Peter Olivi, and probably also from Neoplatonic Peripatetics.

Species and the mental act

Suárez de­scribed the act of knowledge as a “conjunctio objecti cum poten­tia”, and he observed that for this “conjunctio” intentional species are required (CdA, V, 1: 288-90). Their need may be demonstrated on the basis of experience. A real union between object and cognitive power is impossible. Hence, the conjunction occurs “per vicaria objecti speciem”. Furthermore, perceptual and cognitive capabilities in se are ‘indifferent’, that is, they need to be deter­mined by specific contents. In the case of the intellect this determi­nation requires an internal principle, because the human mind can­not be touched by sensible things (CdA, V, 1: 292).

Species are needed to actualize the perceptual and cognitive powers. For this actualization ‘external’ principles, such as the phantasm (in the case of the intellect) or the sensible species re­ceived only in the sense organs (in the case of perception), do not suffice. The material phantasms cannot determine an immaterial faculty, since: «intellectus est potentia alterius ordinis ab omni potentia sen­sitiva: ergo in proprio ordine habet omnia requisita ad [actum] cog­nitionis» (CdA, V, 1: 294). With this concise statement Suárez set bounds to the naturalistic tendencies of Peripatetic psychology, and set out the framework for his own theory of knowledge acquisition. Knowledge is the product of a strictly immanent act, although for its object it de­pends on sensible reality; human cognition is “actio” and not “passio” (CdA, V, 4: 360). The act of cogni­tion does not coincide with the reception or production of a species, but consists essentially in a judgment (Lundberg 1966: 99, 108-109).

Nature and function of the species

Sensible and intelligible species relate to the same object, but in the intellect the species are spiritual and indivisible, while in the senses they are material and divisible (CdA, V, 2: 296f and 316).

The species has a proper being and is distinct from the actual perception or knowledge. Against Caietanus, Suárez argued that the species are accidental and that, for this very reason, knowledge is an accidental union. And since both species and cognition are qualities, the latter cannot be the formal effect of the former. The species should not be seen as the formal cause of intellection, however, but rather as contributing to it “effec­tive” (CdA, V, 2: 300-306, 322).

The mind has an independent activity and, in the generation of its own act, it cannot be ‘formally’ influenced by representations that are connected to sensory capacities. The formal assimilation of the cognitive content occurs in the mental act, for which the intel­lectual soul takes full causal responsibility.

Stressing the causal function of the species while at the same time denying that it may ‘formally’ contribute to the generation of knowledge, Suárez made implicit reference to the fifteenth-century schoolman Crockaert, who used a similar distinction (Spruit 1994: 379-385). When Suárez claimed that the species does not contribute ‘formally’, but only ‘effectively’, to the acquisition of knowledge, he wanted to emphasize that the species is a causal principle that is functional in the specification of mental acts, to be considered only in terms of the task it performs. But what exactly is the role of the species in the economy of human knowledge?

The information conveyed by the species is not a sufficient condition for the production of knowledge. If the act of knowledge would depend only on the species, the soul would no longer be a genuine principle of knowl­edge. Suárez did not accept any real distinction between active and re­ceptive powers in the human soul. Furthermore, the cognitive power cannot be purely receptive, be­cause then human knowledge would depend “ab extrinseco” (CdA, V, 2). Visual experience teaches us to pay attention to what the eyes receive (CdA, V, 4: 350-354). Introducing the notion of attention, Suárez came up with a crucial aspect of his own position, which in fact combines elements from Thomistic and Olivean psychology (Spruit 1994: 215-224).

Suárez came to the conclusion that the causal responsibility for actual knowledge can be attributed only to the cognitive power as informed by the species. In this way he wanted to do justice both to the immanence of the mental act and to its objective refer­ence. Suárez’s conclusion entails that the Scotistic view of a real­ization of the species before the act may be accepted, even in a chronological sense. Actual knowledge is actual assimilation (CdA, V, 4: 364).

Perceptual and mental acts: the generation of species

Suárez discussed the production of the intelligible species in its traditional context, namely, that of the relation between the agent intellect and the phantasms. The need of the former is based on the causal insufficiency of the latter with respect to the intellectual realm. But how do the phantasm and the agent intellect cooper­ate in generating the species? Suárez started his discussion of this question with a review of some of his illustrious predecessors.

Caietanus’ doctrine of an ‘objective’ illumination is summarized in three points: (a) the agent intellect unveils the quidditative essence; (b) before the production of the intelligible species, a uni­versal is abstracted; (c) the illuminated phantasm produces the in­telligible species. Suárez duly identified the most troublesome aspect of Caietanus’ position, namely, that the illumination of the phantasm should precede the production of the intelligible species. No matter how the agent intellect’s assistance to the phantasm is conceived, a material entity cannot be changed by a spiritual agent. Moreover, if the phantasm were capable of repre­senting the universal, then the phantasy should be able to grasp the latter, which is unacceptable (CdA, IX, 2: 82-88).

Suárez also rejected Capreolus’ theory of the phantasm as in­strument of the agent intellect, and his idea of a virtual contact between the two. In the first place, an inferior instrument cannot cause a superior effect. Secondly, it remains unclear what the agent intellect might ‘add’ to the phantasm. Capreolus’ pur­ported solution is thus merely verbal. Other authors have at­tempted to solve the puzzle by assuming that the species is spiritual by virtue of its connection with the agent intellect, and representa­tive by virtue of its sensory origin. According to Suárez, how­ever, these two features of the species cannot be isolated (CdA, IX, 2: 88-90).

The solution proposed by Suárez himself was in effect a combi­nation of views, borrowed on the one hand from Jean de la Rochelle and Olivi (the idea of a “colligantia” or sympathy be­tween mind and body), and on the other hand from Giles of Rome, Capreolus, and Sylvester of Ferrara (the theory of the common “radicatio” of perceptual and cognitive faculties in the human soul). The agent intellect and the phantasy are faculties of the selfsame soul, and their common ‘root’ makes it possible for them to cooperate without any real mutual influence or contact: «Intellectus agens nunquam efficit speciem, nisi a phantasiae cognitione determinetur. (…) Haec determinatio non fit per efficientiam aliquam ipsius phantasmatis, sed per hoc solum quod materiam praebet, et quasi exemplar intellectui agenti, idque propter unionem quam habet in eadem anima» (CdA, IX, 2: 94).

Thus, the production of species is based on a kind of sympathy between ontologically different powers that are integrating parts of the same soul. Intellect and phantasy do not so much causally cooperate, but they have simultaneous or parallel acts (Ludwig 1929: 24, 28, and 50). In the fi­nal conclusion of this chapter, Suárez defined the central operation of the agent intellect’s as consisting essentially in the production of intelligible species (CdA, IX, 2: 98).

Making things actually intelligible, illuminating phantasms, ab­stracting species from phantasms, illustrating the first principles—these are all the selfsame operation. Indeed, the illumination of phantasms may be characterized as the generation of species in the possible intellect which represent at a mental level the content of sensory representations.


Suárez’s specific interpretation of an abstraction of species from phantasms is typical of his idiosyncratic stance in psychology. The intelligible species is not “abstrahabilis” in the sense that it could be mixed with sensory representation, because an accident cannot move from one subject to another. The abstraction is rather a matter of “elevatio” (CdA, IX, 2: 104).

Thus, the abstraction of the species is a purely intramental phe­nomenon, which depends on the phantasm only insofar as the lat­ter’s presence is required (Castellote 1962: 191-192). The phantasm has no instrumental causality; as ‘exemplary cause’ (CdA, IX, 2: 98) it merely offers the occa­sion for a mental operation to take place. Suárez probably believed that the unity of the soul, as the ensemble of perceptual and cogni­tive faculties, is sufficient to explain the relationship between mind and phantasm, in such a way that no causal relation between intel­lect and sensory representation is required for the generation of sense-dependent cognitive contents.

The occasionalist explanation of the sense-dependence of intel­lective cognition is a clear token of Suárez’s affinity with Neoplatonic interpretations of Aristotle’s psychology. An important point of difference should also be mentioned here, however: Suárez did not endorse any type of nativism. The mind produces immaterial representations whenever the inner senses enable it to perform a ‘parallel’ operation. The intelligible species is an exclusive product of the mind, but it is not innate. It arises or emanates in the same instant when the phantasy generates a phantasm (CdA, IX, 8: 236). Elsewhere, Suárez defined this non-essential relationship between the opera­tions of the intellect and the inner sense as “concomitantia” (CdA, IX, 7: 208).

Knowledge conveyed by the intelligible species, produced by the agent intellect, regards singular entities. On the basis of the effects of the agent intellect’s operation, the possible intel­lect may then abstract the universal nature contained in the species of the singular. Thus, the ‘abstraction’ of the intelligible species is attributed to the agent intellect, while the ‘abstraction’ of the universal is attributed to the (informed) possible intellect. As a matter of fact, the universal does not arise from ‘abstraction’, but rather from a process of “comparatio”. The intelligible kernel of substantial reality is known by discursive reasoning on the basis of the information made available by the agent intellect (CdA, IX, 3-4).

Suárez elsewhere qualified the operations of the agent and the possible intellect as “transiens” and “immanens”, respectively (CdA, IX, 8: 212). The possible intellect surpasses the agent intellect in excellence: by producing the species, the agent intellect realizes only the prelimi­nary conditions under which intellective cognition can take place, while this cognition as such depends on the possible intellect alone. The active mind provides the intelligible species: as natural agent it must repair a ‘defect’ in the primary object of cognition, namely its materiality. The agent intellect serves an indispensable in­strumental function, because in its “operari” the human intellect depends on the senses. Once it has been informed, the possible in­tellect may attend to the various aspects of the information con­veyed by the species.

Concluding remark

Suárez’s cognitive psychology sprang from a dialogue with the Scholastic and broader Peripatetic tradi­tion. The (inner) senses have no direct influence on the generation of knowledge, and yet sense-dependent intelligi­ble species are needed, because the mind has no innate contents. Suárez’s position regarding the origin of intelligible species in­volved a fundamental reorientation with regard to the puzzle of reception and generation, which had tantalized so many schoolmen before him. Intelligible species are received only in the sense that they are produced by the agent intellect occasioned by the presence of phantasms. Because the species are sense-dependent, they regard only individuals and not universals. The intelligible species are ef­fective causes, not formal causes. Indeed, the ‘reception’ of species is not sufficient to trigger cognition, which is a purely intramental act.

Suárez ruled out any direct influence of sense on mind, and attached great importance to the mind’s “attentio” in the gen­eration of knowledge. The view that the intramental production of intelligible species is occasioned by the presence of phantasms in the inner senses, also reminds of certain Neoplatonicizing modifications of the species theory. In the time to come it would deeply influence later schoolmen. Moreover, it would pave the way for Descartes’ well-known account of the origin of perceptual ideas, generated by the mind on the occurrence of qualified brain patterns.


  • Castellote S. (1962), Die Anthropologie des Suarez. Beiträge zur spanischen Anthropologie des XVI. und XVII. Jahrhunderts, Karl Alber, München-Freiburg.
  • Ludwig J. (1929), Das akausale Zusammenwirken (sympathia) der Seelenvermögen in der Erkenntnislehre des Suarez, Ludwig Verlag, München.
  • Lundberg M. (1966), Jesuitische Anthro­po­logie und Erziehungslehre in der Frühzeit des Ordens (ca. 1540—ca. 1650), Almqvist & Wiksell, Uppsala.
  • Spruit L. (1994-1995). Species intelligibilis. Form Perception to Knowledge, 2 vols., Brill, Leiden

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