Research Project: “The Shadow Within Nature: Epistemology and Ontology of Prime Matter in the Late Middle Ages (1250-1430)”.

Implementation: KU Leuven, 2020-2023.

Sponsor: Fonds voor Wetenschappelijk Onderzoek – Vlaanderen (FWO senior research fellowship).


The project is centred on philosophical tensions and problems that originated from two crucial questions: first, what is the primordial “prime” matter out of which the physical universe is made? And, second, how can this prime matter be known? In the Latin Middle Ages, answers to both questions were provided by the Aristotelian tradition. For Aristotle, every physical object is a compound of matter and form (a doctrine called “hylomorphism”). The form corresponds to the ontological structure (= making the object be the kind of thing it is) as well as the intelligible content (= what can be known of it) of any hylomorphic compound (= any corporeal thing). In turn, matter corresponds to the “generic stuff” of which a thing is made, like a golden ring is said to be so in virtue of the golden material out of which it is made. As part of this basic metaphysical analysis, the Aristotelian tradition thought that the entire corporeal universe was made out of a primordial, prime matter (πρώτη ὕλη, al-hayula al-ula, materia prima). By definition, this prime matter has no form, therefore it is completely potential and unqualified, lacking any structure, actuality, or epistemic content. The problem of prime matter’s knowability arises here: how can something deprived of any sensible and intelligible form be known? Because prime matter is not perceivable, its knowability had to be achieved only indirectly by intellectual reasoning and complex epistemic strategies.

What is at stake in the epistemological problem concerning prime matter is described exemplarily by the French philosopher Nicole Oresme (1320/5– 1382) in his Questions on Aristotle’s Physics I, 14. If prime matter is to be considered a principle of the natural world, it must be knowable is some way. Indeed, if prime matter were completely inconceivable, this would entail either that the science of nature is based on an epistemic void because prime matter exists but is unknowable or that prime matter does not exist at all and is just a useless conceptual abstraction. That last criticism coincided with the critique expressed by many early modern philosophers. Ontologically remote and unknowable, “natural philosophers cannot indicate the necessity of Aristotle’s prime matter in any way” (Magnen, Democritus reviviscens, I, IV, 79), and of this prime matter “nothing remains that can be clearly understood” (Descartes, Le monde, XI, 33). The idea behind my research project is that this early modern criticism is unfair. In fact, in the context of their nuanced doctrines of prime matter, crucial to both their metaphysics and physics, medieval thinkers elaborated a variety of epistemic strategies to deal with the problem, inherited from Aristotle, of prime matter’s unknowability.

As the above criticism of prime matter suggest, these epistemological doctrines on how prime matter can be known were structurally linked to the ontological theories these thinkers developed about the existence and function of this entity. In the medieval inquiry on prime matter, a mutual interaction is in place between these two levels: indeed, what prime matter is provides the coordinates to the ways by which it is known, yet its conditions of knowability provide both limits and possibility to say what prime matter is. In other words, if I want to know what that spherical red object on my desk is, I have to consider the way by which I can get to know it (= epistemological assessment). For instance, I can touch or taste it and realise that it is an apple (= ontological description). However, in order to assess how I can know that thing, I must have a preliminary information about what it is (= preliminary notion). In my example, I have to see that there is something red on my desk. In the case of prime matter, the preliminary notion is provided by the Aristotelian framework postulating its existence and basic features, the epistemological assessment corresponds to the epistemic strategies to know prime matter, and the ontological description to the metaphysical theories that were elaborated by medieval thinkers.

This is why, in order to properly understand the philosophical problem of prime matter in its complexity, issues of ontology and epistemology must be studied hand in hand. In Metaphysics I, 8, Aristotle claims that matter can be indicated by negation. A primarily logical method, the negative or resolutive strategy consists in a gradual removal of formal qualifications from a bodily thing until, all form removed, prime matter is supposedly reached. In contrast, in Physics A, 7, Aristotle claims that matter can be known by analogy – i.e., a comparison between two or more different sets of things (“domains”) in which a similar function is performed. Aristotle’s set of examples and the poor quality of the Latin translations gave ground to manifold divergent interpretations of how this analogy should be developed. This is particularly true for the 14th century. Different approaches and solutions to the problems surrounding prime matter converged into a more consistent set of ontological problems than in the 13th century. As a result, also the plurality in epistemological strategies is substantively focused on one method in particular, analogy. Structurally linked to the ontological debate, the 14th-century debate on prime matter’s knowability was developed through subtle but significant differences in which the analogical strategy could be employed.

Scientific research objectives

The general aim of my research is to meticulously reconstruct the late medieval debate concerning prime matter, assessing the validity of the initial hypothesis claiming that the epistemic strategies elaborated by later medieval philosophers reflect their particular ontological orientation and therefore can be used to better understand their ontological positions on prime matter. In order to assess the validity of the hypothesis, the research is focused on a selection of late medieval authors chosen for the originality, ingenuity, and long-lasting influence of their contribution to the problems of prime matter’s epistemology and ontology. Reflecting its general purpose, the project aims to achieve two main specific objectives:

O1 – to reconstruct the late medieval ontological debate on prime matter in relation to the epistemological problem of prime matter’s knowability, assessing mutual connections and implications.

O2 – to examine the historical and doctrinal reasons behind the abandonment of alternative epistemic strategies and specifically of the negative method, which was the most common way by which prime matter was said to be knowable since Calcidius (4th century).

To give an idea of the way that the research is conducted and just how much of a contribution it can make, take the cases of John of Jandun (1280–1328), Walter Burley (1275–1344) and William of Ockham (1285–1347). In his Questions on Aristotle’s Metaphysics (VIII, 1), John of Jandun implicitly criticised the negative strategy (= abstraction of forms from matter) as unable to provide a real understanding of prime matter. It is impossible to conceive abstractly prime matter as separated from the form because prime matter is completely passive and therefore unable to “move the intellect.” The reason behind the epistemological impossibility to separate matter from form is the same as its ontological impossibility: to be separable from form, prime matter should exist actually, not potentially. Accordingly, Jandun proposes alternative ways through which prime matter can be known: analogy and the consideration of substantial transmutation. In the latter, prime matter is the potential basic stuff that endures when the thing changes into something else, like a golden ring becomes a golden bracelet, or an embryo a baby.

A somewhat similar idea of prime matter as basic neutral stuff is evoked by Walter Burley’s epistemology. In his Commentary on Aristotle’s Physics (I, p. 54), Burley claimed that prime matter can be known by analogy to either artificial/accidental composites or to the form. However, Burley observes that the analogy to the artificial thing offers a better way to conceive prime matter, as it better displays its role as substrate. Considering a golden ring (= artificial composite), for Burley prime matter is considered as performing a function analogous to that performed by the gold of the golden ring, a sort of basic stuff of the thing. William of Ockham had a somewhat opposite perspective to both Jandun and Burley. In his Summula philosophiae naturalis (I, 9, 180-1), Ockham claimed that prime matter can only be known by its correlation to the form. Indeed, the same relational structure linking together matter and form can be found in every hylomorphic composites. In other words, for Ockham the point is the relational status of matter and form: matter can only be known by form and form by matter. With a more analytical approach than Jandun and Burley, Ockham appears to stress the role of prime matter as substrate of inherence (= what “instantiates” the form) rather than substrate of endurance (= what endures through change).

These examples show that the epistemic strategies adopted by Jandun, Burley, and Ockham were evidently linked to their preliminary ontological considerations of prime matter. However, what does the assumption that matter is knowable by analogy to the form, the composite, or substantial change imply for the ontological and physical theories of matter proposed by these authors? And what epistemological and ontological reasons were behind their choice of one strategy over the others? Initial research suggests a wide plurality of approaches and epistemic strategies in relation to the ontological stakes of the doctrine of prime matter, with different implications. My research aims to examine these ontological claims from an epistemological angle and to reconstruct late medieval discussion on prime matter. As a consequence, my research is open to an overall reassessment of this central aspect of the history of ontology. This overall reassessment of the theory of prime matter has the added benefit of being able to provide historical foundations for the ongoing scholarly debate on the applicability of the Aristotelian framework in contemporary metaphysics and philosophy of science.

The project implementation corresponds to a thorough assessment of the initial hypothesis and the achievement of O1 and O2. Accordingly, my research examines the doctrines formulated by extremely important thinkers in the period 1250-1400, who have been selected for the originality and later influence of their positions. Since the project aims to reconstruct as fully as possible the historical debate on prime matter in the period, the research is no limited to these thinkers. Yet the focus is centred on these key authors and on a specific set of works they authored. What are the correlations between the epistemological doctrines and the ontological descriptions of prime matter proposed by these thinkers? How were these epistemic strategies useful in their efforts to construe a coherent doctrine of prime matter and resolve the manifold problems related to it? And finally, what connections were there between the admission that prime matter can be known and the physical inquiry into the properties of natural bodies? In order to check the validity of the field hypothesis and achieve O1 and O2, my research adopts two interconnected methodologies: historical method and systematic analysis.

© 2020 Nicola Polloni