Knowing the Shadow: Ontology and Epistemology of Matter in the Thirteenth Century

Implementation: Humboldt Universität zu Berlin, 2018-2020.

Funding Institution: Alexander von Humboldt Stiftung

Knowing the Shadow aims at analysing the theoretical development that marked the transition from the philosophical concept of matter as ‘ontological substrate of a specific region of caused being’, to the early-scientific notion of matter as ‘individual possession of a physical quantity/mass’, common to both celestial and sublunary beings, and specified into a varying number of primary mixtures. This course is accompanied by an ‘epistemological emancipation’ of the notion of matter. The admission of its ontological determination, indeed, implied that matter was knowable, and thus, operable and ‘experientiable.’ This is the very pre-requisite for a quantification and, later, mathematisation of matter as mass and quantity, and its admission would put at stake the overall theory of knowledge proposed by the Aristotelian tradition, and based on forms and abstraction from matter

My research aims at providing a systematic, overall, and updated analysis of the thirteenth-century debate on matter and the role played by Ibn Gabirol, Avicenna, and Averroes on those discussions. Especially, the project intends to thematise the unstated question on the knowability of matter, the influence matter has on the human intellective process as gnoseological limit, and the possibility of having any kind of knowledge of the material substrate, the very prerequisite for the subsequent quantification of matter as mathematizing object. These two aspects—the ontological and epistemological problem—are the two faces of the gradual process that led to the recognition of an ontological determination proper to matter during the thirteenth century.

The problems on the ontological and epistemological status of matter accompany the very emergence of this concept with Plato (matter as chora, elementary substrate, and necessity; which is known through a ‘spurious reasoning’) and Aristotle (matter as undetermined, potential, and eternal substrate of any change in corporeal bodies; which is known through its correlation to form). Until the twelfth century, the Latin tradition addressed the question on matter through the authoritative accounts of Calcidius, Boethius, and Augustine. Then, the Greek- and Arabic-into-Latin translation movements, in a relatively short lapse of time, made available crucial works by Aristotle (absent from Europe since centuries), together with many Arabic and Greek authors whose influence will be pivotal for the medieval philosophical debate. Among them, the most influential authors on the discussion of matter were Ibn Gabirol, Avicenna, and Averroes.

Ibn Gabirol provided the Latin debate with a peculiar theory of matter, centred on universal hylomorphism. Matter and form are the original components of every created being (both spiritual and corporeal), and are actualised only when they are joined together. The universe is then created through a process of progressive hylomorphic unions, where matter plays a primary role in its direct derivation from God’s essence. This overturns the traditional characterisations of matter: the substrate is caused by the most essential character of God, and its knowledge is necessary to understand God’s most intimate aspects.

On the contrary, for Avicenna, prime matter is the completely potential and undetermined substrate of corporeal bodies only. Since it is utterly potential, per se matter is unextended, and requires a corporeal form (forma corporalis, ṣura jismiyya), an accident which provides matter its extension, continuity, and divisibility. Matter constitutes also the physical specification of the structural duplicity proper to every caused being, an ontological complexity expressing the difference between God and caused universe. By a certain viewpoint, Averroes’s definition of matter is close to Avicenna’s. Averroes, too, claims that prime matter is the substrate of every corporeal being, characterised by its potency, eternity and privation of any form. Matter, nonetheless, does not coincide with potency: as substrate of every corporeal being, potency happens to matter since it can be joined by potentially every form, and thus, its potency is accidental and non-essential to matter. Moreover, in the sublunary world matter is always accompanied by its undetermined dimensions, which makes matter extended, divisible and persistent through the substantial change.

Together with Aristotle, these three Arabic sources will have a wide and profound influence on the Latin discussion on the puzzling questions over matter. Ibn Gabirol, Avicenna, and Averroes present three different and even opposite solutions to the long-lasting problems of matter, and the Latin thinkers will receive, criticise, and often combine these three perspectives in very different ways.

A first aspect of the thirteenth-century discussion is related to the ‘ontological extension’ of matter, that is, Ibn Gabirol’s universal hylomorphism opposed to the corporeal hylomorphism (Aristotle, Avicenna, Averroes). In general, the Franciscan thinkers tended to accept the theory universal hylomorphism, and some of them (Bonavenure, Bacon, Peckam, Olivi) defended this perspective throughout their philosophical production. Others (Duns Scotus, Ockham) did not adhere to this theory, but agreed with the implicit correlate of Ibn Gabirol’s position, the theory of plurality of substantial forms. In further cases (Albert the Great), this doctrinal point was diffusedly discussed, while some thinkers (especially Aquinas) dedicated fiery pages to the refutation of the ‘Gabirolian errors’. The first task of the proposed research will be to clarify the development, mutual interconnections, and shared sources of this debate, pointing out the theoretical reasons which caused the progressive abandonment of universal hylomorphism.

Connected to the problem of the ontological extension of matter is the question on the number of existing matters. While the tradition seemed to be coincident in claiming the existence of one matter only, which is common to every corporeal being (or caused being in general), on the one hand, the radical differences among genera and, on the other hand, the necessary justification of the differences among the matter/s of individual beings (i.e., the principle of identification), made the traditional account more problematic to accept. In some cases — and often from opposite viewpoints — medieval philosophers firmly continued to accept the existence of a single matter (Bonaventure, Aquinas), and consequently they tried to find elsewhere a principle of individuation and material distinction. In other cases, the solution was to suppose a varying number of matters (three different matters progressively informed for Bacon; two matters, corporeal extended and spiritual unextended matter, for Olivi); or even to admit an intrinsic division of matter, always already individuated into particular matters (Ockham).

How are these different solutions connected to the problem on the ‘ontological extension’ of matter? From a universal hylomorphic perspective, are Bacon’s and Olivi’s position admissible? And, finally, what are the conceptual consequences of admitting a plurality of individuated matters regarding the notion of matter? The research herein proposed will deal with these and further questions, underlying the origins of this problem through the analysis of the Arabic sources and their interpretation of Aristotle.

Beside Ockham’s position, the most common solution to the problem of individuation and persistence of matter was to appeal to the quantitative and/or extensive dimensions of the substrate. The admission of a potential and undetermined state of matter implied the necessity of an external cause of individuation/preparedness of matter before its union with the substantial form: if matter is the common substrate of every form, not every form joins the whole of matter, but a single substantial form informs a specific portion/region of matter. By this, the individuation of matter had to be caused by something non-substantial (i.e., an accident) which joins matter before the substantial form.

Since this accident had to perform the individuation of matter, in general, into a particular region of matter prepared to receive its form, the thirteenth-century philosophers often identified this accident with the extension or quantity of matter. On the one hand, echoing Avicenna, Aquinas elaborated his famous doctrine of ‘matter marked by quantity’ (materia quantitate signata), stating that an accidental quantity individuates matter and persists through the substantial change. On the other hand, following Averroes, other thinkers proposed different solutions to this problem, based on Averroes’s doctrine of undetermined dimensions (Henry of Ghent) and focused on the ‘quantity of matter’ (Giles of Rome) or the ‘passive extension’ of matter (Walter Burley). In this way, they claimed that matter possesses an accidental determination expressing its potential quantity/extension before being joined to its substantial form: since this accidental determination always accompanies matter, the result of this approach is that the undetermined substrate, matter, becomes marginally determined.

This tendency will find two of its most radical proponents by the end of the century. On the one hand, Duns Scotus—who famously opposed to Aquinas’s materia signata his theory of ‘thisness’ (haecceitas)—stated that matter has a real existence, an actual being that would make even possible, at least to God, its subsistence without any form. On the other hand, Ockham’s claim that matter is essentially divided into particularised parts allowed him to deny any principle of individuation and corporeity. The debate on matter’s individuation and extension marks a crucial development of the notion of matter in the Middle Ages. The problem that the project will address is whether is detectable, or not, a process of progressive characterisation of matter as extended and quantified shared by the philosophers animating this discussion, and what is the impact the Arabic sources had on this process.

This variety of approaches and solutions to the ontological problems concerning matter is in place also regarding the possibilities of its knowledge: indeed, matter can be known only if is at least marginally determined. On the one hand, denying any actual subsistence of matter, Aquinas had to state that neither human beings nor God can have a direct knowledge of it, if not a mediated conception through the body. On the other hand, Ockham’s peculiar concept of matter allowed him to claim the knowability of the substrate: matter can be known even though with a precarious kind of knowledge due to the deficiency of human intellectual powers. Between these extreme positions, the Latin debate offers a wide number of different theories, in a discussion bound to the progressive recognition of an ontological subsistence of matter. The project will specifically deal with this epistemic problem, analysing it under two different respects: on the one hand, the knowability of matter (how can matter be known through a intellective dynamic based on forms?), on the other hand, the accidental role played by matter in the abstractive process (What matter gives us through the abstraction from it?).

Finally, there is a further, specific aspect of this debate that is crucial for an overall understanding of the debate on matter. It is the consideration of the ‘practical experience’ of matter described by two pivotal alchemical writings of the time—the Latin Geber and pseudo-Llull—where matter is not only subsistent and knowable, but also operable. This ‘alchemical’ matter is rather different for the two authors, presented as a single matter decayed into various degrees of existence (pseudo-Llull), or an aggregate of minuscule corpuscular beings (Latin Geber). Both descriptions are exemplar cases of the first development of the practical notions of matter, moments of a fil rouge which arrives to Boyle’s The Skeptical Chymist. The proposed research will examine their discussions of matter and how these discussions rely on the philosophical debate on matter.