Between physics and metaphysics: Mulla Sadra on nature and motion

Islam & Science, June, 2003 by Ibrahim Kalin

Mulla Sadra's concept of nature and substantial motion treats many aspects of traditional philosophy and cosmology in a new light. By allowing change in the category of substance (jawhar), Sadra goes beyond the Aristotelian framework followed by the Peripatetics and Suhrawardi, turning substance into a 'structure of events' and motion into a 'process of change'. Sadra's reworking of classical cosmology through his elaborate ontology and natural philosophy leads to a new vocabulary of 'relations' and fluid structures as opposed to 'things' and solidified entities. In his attempt to make change an intrinsic quality of the substantial transformation of things, Sadra posits nature (tabi'ah) as the principle of both change and permanence, thus granting it relative autonomy as a self-subsisting reality. What underlies Sadra's considerations of change and nature, however, is his concept of being (al-wujud) and its modalities. Change as a mode of being and the de-solidification of the physical world goes beyond locomotive and positional movement, and underscores the dynamism of the world-picture envisaged by Sadra's gradational ontology.

Keywords: Sadra; nature; change; substance; ontology; being; actuality; potentiality; matter; permanence; form; motion/movement.

Mulla Sadra's concept of substantial motion (al-harakat al-jawhariyyah) represents a major departure from the Peripatetic concept of change, and lends itself to a set of new possibilities in traditional Islamic philosophy and cosmology. By defining all change as substantial-existential alterity in the nature of things, Sadra moves away from change as a doctrine of external relations, as Greek and Islamic atomism had proposed, to a process of existential transformation whereby things become ontologically 'more' or 'less' when undergoing change. In his considerations of quantitative and qualitative change, Sadra takes a thoroughly ontological approach and places his world-picture within the larger context of his gradational ontology. Substantial motion and the dynamic view of the universe that it espouses can thus be seen as a logical extension of the primacy (asalah) and gradation of being (tashkik al-wujud)--two key terms of Sadrean ontology. Sadra relegates all reality, physical or otherwise, to the infinitely variegated and all-encompassing reality of being, and this enables him to see all change in terms of being and its modalities (anha' al-wujud). Although Sadra accepts a good part of the Aristotelian view of motion and its types, it is this ontological framework that distinguishes his highly original theory of substantial motion from the traditional Peripatetic discussions of motion.

In what follows, I shall give a detailed analysis of substantial motion and the ways in which Sadra incorporates and reformulates the traditional notions of qualitative and quantitative change in his natural philosophy. It should be emphasized at the outset that Sadra's views on nature and motion are not an isolated set of philosophical reflections but are rather closely related to his ontology and cosmology on the one hand, and psychology and epistemology, on the other. This is borne out by the fact that many of Sadra's novel contributions to Islamic philosophy are predicated upon substantial motion, among which we may mention his celebrated doctrine that the soul is "bodily in its origination, spiritual in its subsistence" (jismaniyyat al-huduth ruhaniyyat al-baqa') and the unification of the intellect and the intelligible (ittihad al-caqil wabl-macqul). In this essay, I shall limit my discussion to Sadra's attempt to move away from a framework of external relations and positional motion to a framework of existential transformation whereby the cosmos is projected as marching towards a universal telos.

The Aristotelian Framework: Motion as the Actualization of Potentiality

Following the scheme of Aristotelian physics, Sadra begins his discussion of motion by explaining the meaning of potentiality. The word potentiality (al-quwwah)(1) is defined in several ways. The most common meaning is the ability to execute certain actions. In this sense, al-quwwah as potency is synonymous with power (al-qudrah), which renders the motion or action of physical bodies possible. Ibn Sina gives a similar definition when he says that "potentiality is the principle of changing into something else". (2) All beings that undergo quantitative or positional change use this potential power. Such corporeal bodies, however, need an active agent to actualize their dormant potentiality. For Sadra, this proves that a thing cannot be the source of change by itself, and there must be an outside factor to induce it to change. If the source of a quality or 'meaning' (ma'na) in an entity were to be the thing itself, this would amount to an unchanging nature in that thing. The real nature of possible beings, however, displays a different structure. With Aristotle (3) and Ibn Sina (4), Sadra takes this to mean that "a thing cannot have its principle of change in itself" and that "for every moving body, there is a mover outside itself". (5)