What is the ontological difference between potentiality (dunamis, in Greek) and being in potentiality (dunamei, dunaton)? David Lefebvre and Kristell Trego, in their recently published collection of essays on the reception and transformation of Aristotle’s views on the possible in later periods of the history of philosophy, tacitly (and rightly) assume there is a significant difference between potentiality and being in potentiality. They identify Aristotle as the ‘inventeur de l’être en puissance’ (their words), which I read as an implicit recognition that he isn’t (also) the ‘inventeur de la puissance’ (my words). Put differently, Aristotle has introduced in the history of Western metaphysics not causal powers themselves, but a certain conception of causal powers, as grounding modality, i.e. what’s possible (or impossible, and therefore necessarily not the case). Before coming to explain Aristotle’s position, I want to address the question of the difference between treating Aristotle as the ‘inventeur de l’être en puissance’ rather than the ‘inventeur de la puissance’.
Causal powers, as we conceive of them, are (types of) properties essentially defined by the (type of) change they enable their possessor to bring about or suffer. They may exist as inactive, or as actively exercising. Their exercise makes a causal difference to the world, either because what’s endowed of causal powers changes itself (intransitively, e.g. when uranium decays), or because it changes something else (transitively, e.g. when a magnet attracts metal), or both (e.g. when a lump of sugar sweetens a cup of coffee and dissolves in it). As I argued elsewhere, this way of thinking about causal powers, which is mainstream in the history of philosophy, was not however the way pre-Aristotelians thought; it is rather a theoretical acquisition that we owe to Aristotle.[1] Before Aristotle, causal powers were central to many, if not all ancient metaphysical systems, including Plato’s; but powers were thought to make a difference to the causal profile of the world without interaction, without becoming activated, for there was no distinction between powers in potentiality and activated powers. Powers existed as always active. Aristotle is the first in the history of metaphysics to distinguish between two states of a power: in potentiality and in actuality.[2]
This is what is significant in the stance that underpins Lefebvre’s and Trego’s editorial project (and that Lefebvre had argued for elsewhere, too):[3] the recognition that Aristotle is the first to ground modality on potentiality, and thus the first to explain what’s possible in the natural world in terms of the powers that exist in nature and the occurring conditions for their exercise. In a physical world, such as that modelled by Aristotle’s predecessors, the possibility of change is left unexplained (as in Plato) or attributed to supernatural causes (as in Anaxagoras, with nous). Anaxagoras’s and Plato’s powers are continuously exercising causal efficacy (by their mere presence in the world); there is no transition in their systems from potentiality to actuality—this would be barred for them by Parmenidean considerations. By contrast, for Aristotle, powers in potentiality come to be actualised, either as agents of change or as patients of change, as active powers exercising their influence on passive powers, or as passive powers suffering such influence (e.g. in a process like housebuilding, when the builder exercises their active powers on the building materials’ passive powers). In becoming actualised (that is, transitioning from the state of being in potentiality to the state of being in actuality), powers bring about change. So powers account for change in the world, in Aristotle’s system. This is his innovation in relation to his predecessors.
To recapitulate: previous thinkers had already introduced causal powers at the fundamental level of their metaphysics, but Aristotle is the first who posited that causal powers may exist in two states: active (in actuality), or inactive (in potentiality), and the first who grounded modality on this difference in the powers’ states: their being activated upon the occurrence of the appropriate circumstances is contingent upon the circumstances presenting themselves, but necessary if the circumstances are ‘right’.[4]
In assuming that Aristotle invented (although I would say: discovered) a certain conception of causal powers rather than causal powers themselves, Lefebvre and Trego shift what has been a trend in recent years in the relevant French scholarship. Previous recent work in French on ancient Greek metaphysics of powers includes for example edited volumes such as: Dunamis: Autour De La Puissance Chez Aristote (2008) edited by M. Crubellier, A. Jaulin, D. Lefebvre, P.-M. Morel (to which Lefebvre and Trego make themselves reference in their introduction), but also Essence, Puissance, Activité Dans la Philosophie et les Savoirs Grecs (2022) edited by A. Lecerf, G. Casas, and P. Hoffman;[5] and monographs such as Dieu sans la puissance. Dunamis et Energeia Chez Aristote et Chez Plotin (2006) by G. Aubry. These and other publications have focused (by and large) on which types of causal powers different ancient thinkers have posited in their metaphysics, while Lefebvre and Trego, as I read them, want to bring to the fore the idea that, with Aristotle (and his followers), causal powers are explanans of modal/causal phenomena. This is not an uncontroversial view in metaphysics. By means of their edited volume on the reception and transformation of Aristotle’s stance, Lefebvre and Trego do not only contribute to expand our knowledge of historical theories of powers, which other French scholars have also done, but more uniquely in relation to the state-of-the-art concerning the history of the metaphysics of causal powers, they highlight, as a fil rouge through historical thinkers as different as e.g. Alexander of Aphrodisias, Leibniz, Hegel, Husserl, Heidegger (to mention a few), how Aristotle’s approach to powers and modality was received and endorsed/transformed in later periods.
It is an impossible task to provide full details on the various interesting points of view that the thirteen diverse chapters in the volume bring to our understanding of Aristotle’s ‘heritage’, as the editors call it, in the subsequent periods in the history of philosophy where modality is discussed. Three chapters are on ancient and late antique conceptions of powers (Delcominette on Aristotle, Lefebvre on Alexander of Aphrodisias, Petit on Plotinus); one covers the medieval period (with focus on Avicenna and Duns Scotus, by Trego); one Leibniz (Pelletier); one the ‘materialists’ of the French Enlightenment (Bardout); from there we move to Husserl and Meinong (Gérard) to Heidegger (Blanchet) to Levinas (Serban). The final three chapters discuss ‘the possible’ from the perspective of contemporary analytic metaphysics (Chauvier, Halimi, Drapeau Viera Contim).
Delcominette discusses the problem of how the infinite is in potentiality (and its relation to matter), according to Aristotle. Lefebvre addresses the problem of how something can have a potentiality for contrary effects, according to Alexander of Aphrodisias, and concludes that for him matter/the substratum receives simultaneously two potentialities, one for a contrary each. Petit presents Plotinus’ views on potentiality as receptivity.
Trego uncovers Avicenna’s influence on Duns Scotus, surprisingly showing that the former’s theoretical reflections on necessitarianism open the way for the latter to argue for the contingency of causation.
Pellettier argues that ‘the possible’ is not outside the actual world for Leibniz, contrary to what the mainstream scholarship takes him to hold.
Bardout shows how the ‘materialists’ of the French enlightenment (La Mettrie, Helvetius, Diderot and d’Holbac) come to rehabilitate, after their period of disgrace as scholastic intellectual ‘junk’, Aristotle’s ideas about potentiality, dispositions, the possible, which the ‘materialists’ put to use to argue for the self-development of matter.
Touchard explores whether Hegel’s Aristotelianism includes the ontological distinction between potentiality and actuality, with special reference to what Aristotle thinks of the prime mover in Metaphysics Lamda, and how this impacts Hegel.
Gérard takes us to Husserl, who understands the possible as that which does not violate any laws; but clearly the key to understanding this stance is to understand what laws are, for Husserl, which the author discusses in his chapter.
Blanchet teases apart two interpretative approaches that Heidegger takes with respect to Aristotle, and in particular here of potentiality and ‘the possible’, at different points in his continuing engagements Aristotle. Yet the ‘fil conducteur’ between the two approaches is that for Heidegger what is possible in the highest degree is that which has the least positive determination, and thus only a negative account.
Serban explores the ethical implications of Levinas’ understanding of ‘the possible’ and concludes the sequence of historical chapters in the volume.
In the group of the three final chapters devoted to contemporary analytic metaphysics, Chauvier discusses the so-called Master Argument about time, possibility, and determinism; Halimi the possible, the impossible and the necessary; and Drapeau Viera Contim defends the plausibility of a metaphysics of modality grounded on potentiality, even at the cost of admitting the (metaphysically) necessary existence of at least one concrete object.
Given that the chapters range from Alexander of Aphrodisias, the Greek, Arabic and Latin medieval tradition, Leibniz, Descartes, Hegel, Husserl, Meinong, Heidegger, and Levinas, to discussing how contemporary analytic metaphysics takes on Aristotle’s approach, the book is a true philosophical feast, with much to offer to a great diversity of readers.
Notes
[1] ‘Causal Powers in Aristotle and his Predecessors’, in J. Jorati (ed.) Powers. A History, Oxford Philosophical Concepts, OUP, 2021, pp. 10-27.
[2] See e.g. Metaphysics 1049b12-15.
[3] Dynamis. Sens et Genèse de la Notione Aristotelicienne de Puissance (2018), Vrin – Bibliothèque d’Histoire de la Philosophie.
[4] Once the appropriate circumstances occur, then necessarily the agent power acts on the passive power and brings about its effect (see e.g. Metaphysics 1047b35-1048a8 and Physics 202a5-9). This is what we call nowadays conditional necessity. But whether the circumstances occur or not, it is a matter of contingency.
[5] Reviewed in BMCR 2023.10.19.