Thought

As a central figure of the thirteenth century philosophy and theology, both in Paris and in Oxford, Kilwardby was influenced by, and in some cases in contact with, authors as Robert Grosseteste, Richard Fishacre, Richard Rufus of Cornwall, and Bonaventure. The presence of Bonaventure in Kilwardby’s Sentence commentary seems clear, for example on the topic of Trinitarian theology, and the influence of Rufus has also been noted (Wood 2001), but further research is needed. On the other hand, researchers have been stressing the influence of Kilwardby’s commentaries (Categories, Prior and Posterior Analytics) on Albert the Great (Ebbesen 1981; Cannone 2002; Thom 2007), and Roger Bacon (de Libera 1987), but also Lambert of Auxerre, Simon of Faversham, Radulphus Brito, and Richard of Campsall (Lagerlund 2000). Worth mentioning are the ontological implications of Kilwardby’s theory, namely his focus on syllogisms with propositions that express per se necessities, which implies an essential relation between subject and predicate (Lagerlund 2000). A proposition correctly formulated expresses something essential about the reality, and the way we understand reality (Thom 2007). Logic is the science of reasoning, and knowledge is acquired through demonstrative syllogism. Matter and form analysis is employed to syllogisms and propositions but also to words. Words are made up of utterance (vox), and act of signifying. Meaning is the relation of a sign to that of which it is a sign (Lewry 1978, 1981b). Kilwardby’s grammatical theory was equally influential. In his commentary on the Priscianus minor, Kilwardby analyzes the correction (congruitas) and the completeness (perfectio) of sentences in cases where the rules of construction are not observed. It is the case of figurative constructions, which he considers ungrammatical simpliciter but congruous secundum quid, with relation to the meaning intended by the speaker (i. e., a criterion of grammaticality based on the authorial intent: Sirridge 1990). The sentence is acceptable because the hearer has the capacity to, from the meaning of the ill-formed utterance, to understand what the meaning intended by the speaker was (Rosier 1994). Nevertheless, a normal construction represents the intention of the speaker in correct grammatical terms (Kneepkens 1984).

After 1240-1244, Kilwardby comments on the Ethica vetus et nova, that is, books I-III of the Ethica Nicomachea (Lewry 1986). Together with his course on the logica vetus, it constitutes the most comprehensive set of commentaries of a master of Arts that has survived. In both cases he introduces the works according to Aristotelian doctrine of the four causes: the material cause concerns the subject of the work in question, the formal cause the mode of procedure (modus and ordo), the final cause the purpose of the work (utilitas), and the efficient cause the authorship (Lewry 1978). The importance of Kilwardby’s commentary on the Ethica resides in the ability of the Dominican to distinguish between the Aristotelian and Christian understanding of virtue, as in the analysis of happiness, virtue, and human goodness in philosophical rather than theological terms. The philosophical happiness (felicitas) is taken as not coincident with the theological beatitude (beatitudo) (Celano 1986,1999). By holdingwith Aristotle that human virtuous actions are the cause of happiness, and not the union with God that the theological reading stressed, Kilwardby departs from the positions of his contemporaries. Kilwardby explains that, for Aristotle, happiness is attainable by human beings during their life (Lewry 1986; Celano 1986). In his works, Kilwardby shows an acquaintance with the works of Aristotle, not limited either to the works commented or to commonplaces (Lewry 1978; Brown 1996; against Long 1996), as well as an attempt to provide an accurate and systematized account of Aristotle’s text (Thom 2007).

The influence of Averroes is felt in Kilwardby’s logic (Lewry 1978; Lagerlund 2000; Cannone 2002) and natural philosophy (McAleer 1999). On two topics, however, Kilwardby criticizes Averroes: on the dependence of the unity of time on celestial motion in the De tempore, and on Averroes’ theory of one soul common to all human beings. About the latter, Kilwardby considers it to be contrary to philosophical truth, faith, and even Aristotle’s intention. Kilwardby argues against Averroes, that only with respect to the different parts of the same body can the soul be one (and not to different bodies). Moreover, as the soul is the form of the body (forma corporis est anima), there cannot be the same form for all men. Finally, if there would be only one soul to all men, the same soul would know and ignore, be saved, and damned. Moreover, Kilwardby claims the intellects of different human beings are distinct even when they have the same object of thought because the intelligible is one only in species and not numerically (simulacrum eiusdem rei sensibilis a diversis intellectum non est idem numero sed specie solum). Plato’s likeness is the same only according to the species in the minds of Socrates and Cicero. Universals, which exist in the divine mind as causal forms or exemplars, exist both in the human mind and in real things. As the essences of real individual things, universals are abstracted by the mind from the species received through the senses. The mind considers that which is common to the multitude of the images, therefore the unity of the universal is based ‘‘on agreement in essence’’ (convenientia essentiae) (Lewry 1981).

Kilwardby is also the author of a widely circulated introduction to the arts (their classificatory scheme, the definition of their objects and methods), the De ortu scientiarum, written c. 1250, which has been qualified as an optimistic encyclopedia. It is based on the Aristotelian notion of science and on the model of Hugh of St. Victor’s Didascalicon de studio legendi, although the influence of other classificatory schemes can be found, for example, Gundissalinus’ De divisione philosophiae (Alessio 2001). Philosophy is defined as the study of both divine and human things, in order to live virtuously. Also in his commentary on the Ethica vetus et nova, Kilwardby stresses that knowledge is motivated by a moral end (Celano 1999), and in the introduction to the Isagoge he insists in the perfection of the soul by knowledge and virtue (Lewry 1978). Philosophy (scientia humana commendabilis) is divided in speculativa (which is further divided into naturalis, mathematica, and divina), activa (which is further divided into mechanica and ethica), and sermocinalis (which is further divided into grammatica, logica, and rhetorica). Following Hugh, Kilwardby includes the mechanical arts in the classificatory scheme, with some terminological changes in order to approach them to the social-economical context (Alessio 2001), and the replacing the theatrica for the architectonica. As in Hugh, magic (scientia humana vituperabilis) is excluded from the sciences.

It is in the De ortu as well as in two later works, the De 43 questionibus (from 1271) and the Epistola (from 1277 to 1278), that we find Kilwardby’s notion of materia naturalis or physica. Natural matter is impregnated with active potencies, which Kilwardby identifies with the Augustin-ian seminal reasons. Active potencies are potencies because ordered to actuality, striving for form, and as to strive (appetere) is some kind of action, it is some kind of form. Natural matter is impregnated with active potencies, which correspond to forms in an incomplete state, that is, the difference between the complete form and the active potency is their degree of actuality and not a difference of essence. The active potencies, transmitted with the semen, are educed from matter, through the action of the corporeal spirit, as the vegetative and sensitive forms of the soul. The being receives the intellective form at a certain stage of fetal development (Silva2007). The double origin justifies, together with the principle that each form is responsible for certain operations, the composite nature of the human soul. The vegetative and the sensitive forms are qualified as the principle of life because through them the being performs the operations of life, while the intellective form is created by God, is not act of any part of the body, and does not operate through bodily organs. The intellective soul is a hoc aliquid and the perfection of the sensitive body. Once infused, the intellective potency connects the previous potencies (vegetative and sensitive), completing and perfecting them. The three substantial forms constitute one composite unity due to their natural inclination to each other and to the body. The relation of the rational soul with the body is essential and not accidental, being precisely that which distinguishes the human and angelic rational soul (both are composed of a material together with a formal principle, in a declaration of universal hylemorphism). Also the body is a composite substance constituted by an ordered series of forms. For all this, Kilwardby is said to hold a plurality of substantial forms in human beings.

Kilwardby also wrote a commentary on the Sentences, in the form of questions (c. 1256). Kilwardby discusses, especially in questions 35-36 of the first book, the problem of the Trinity. The persons are distinguished in the following way. God Father begets God Son from His own substance and the Holy Spirit proceeds from both. The origin, and the way of being originated, brings about opposite relations between the persons: generating, being generated, and proceeding. Divine persons are relations, not in the sense of inhering (otherwise they would be accidents), but in the sense of being related to something extra se (and as such are substances). Moreover, love comes from knowledge. The Father and the Son know each other as they are, and the love which arises from this knowledge is the Holy Spirit. An analogous reasoning is applied to the human rational soul, as the image of the divine Trinity.

Although there is a certain continuity of thought between Kilwardby’s Parisian and Oxford periods, namely by his use of logical reasoning into theological questions, at least on two subjects Kilwardby changed his mind. The first concerns the cause of movement of celestial bodies, and the second the cause of individuation. About the former, while earlier he holds that celestial bodies are moved by their intelligence, later Kilwardby prefers the original solution from John Blund’s Tractatus de anima, that is, the natural inclination of the celestial bodies’ own weight (Silva 2007). In both solutions, Kilwardby is arguing for celestial motion to be a natural rather than violent motion, as in both cases the cause of motion is internal to the thing moved. About the latter, in his Sentences commentary, Kilwardby argues that both matter and form are intrinsic causes for individuation: matter as the passive cause (causa receptiva), form as the active cause. This particular individual actual being (ens actuale et individuum) is the actual designation (signatio actualis) of matter by form. Form designates matter, and designating matter, designates itself secundum diversas rationes. The individual property is actual existence. This individual property, that is, the actual existence of the individual, is substantial to the individual and accidental to the species.

A central issue in Kilwardby’s work is the attempt to conciliate the philosophy of Aristotle and Augustine (Lewry 1983), and when this proves not to be possible, he sacrifices Aristotle in favor of Augustine. This is particularly acute in his De spiritu fantastico (1256-1261). The Aristotelian scent given by the subtitle of the text - de receptione speciarum - is compensated by the strong Augustinianism present in the text. Apart from Augustine and Aristotle, this work also displays the influence of Jean de la Rochelle’s Tractatus, Costa ben Luca’s De differentia spiritus et anima, and Pseudo-Augustine’s De spiritu et anima (Lewry 1983). For Kilwardby, sensible knowledge is based on sense experience, that is, the sense object impresses the sensible species in the sense organ. However, the passivity of the senses is tempered by the activity of the sensory soul, the efficient cause per se of the sensible knowledge. Kilwardby offers two accounts for sense perception, one focusing on the reception of the species and the activity of the internal spirits (vital and animal) together with the system of ventricular location of the powers of the soul; the other focusing on the activity of the soul, immaterial and dynamic, capable of producing from and by itself the images of the sensible objects. This activity of the soul in the process of sense perception consists of two motions: the sensitive soul reacting (simultaneously, due to the spiritual nature of the soul) to the affection of the body, which results in the soul making an image from the species impressed in the sense organ; the second motion consists on the soul, after stopping paying attention to the exterior object, turning itself and seeing the image made in itself, through which the object is then perceived (Silva 2008). The result of this action is then kept by the power of memory. Kilwardby explicates the existence of three distinct memories: the lower (brutalis), which we have in common with animals and that belongs to the sensitive part of the soul; the middle memory (rationalis inferior et exterior), which belongs to the rational part of the soul, and is related with sensible knowledge; and finally, the higher rational memory (rationalis superior et interior), which is dedicated to intellectual knowledge.

See also: > Albert the Great > Augustine > Avicebron

>  Bonaventure > Categories, Commentaries on Aristotle’s

>  Change and Motion > Dominicus Gundissalinus

>  Epistemology > Ethics > Happiness > Hugh of St. Victor > Ibn Rushd, Muhammad ibn Ahmad al-Hafid (Averroes) > Natural Philosophy > Parisian Condemnation of 1277 > Philosophical Psychology > Posterior Analytics, Commentaries on Aristotle’s > Prior Analytics, Commentaries on Aristotle’s > Richard Fishacre

>  Richard Rufus of Cornwall > Robert Grosseteste

>  Sense Perception, Theories of > Syllogism, Theories of

>  Thomas Aquinas > Trinity > Universals