Aristotelianism

Time on the Aristotelian view is the number of motion in respect of before and after — a measure inseparable from the changes that material substances undergo as they actualise their potentials. It is substantival enough to be measured but ontologically dependent on the substances whose activities it tracks. Aquinas extended this account with the further distinction between time, aeviternity, and eternity to handle creatures with different relations to change. Practical reasoning is itself temporally extended: phronesis adjusts the virtues to changing particulars across a complete life, and eudaimonia is achieved only over the whole of a lifetime, not in any single moment.

Space is finite and concrete on the Aristotelian account — the cosmos of the Physics is a bounded, hierarchically ordered place in which each substance has its natural location and characteristic motion. Modern Aristotelians have largely accepted post-Galilean physics for the description of celestial motion, but the conceptual orientation persists: substances are spatially situated, and place (topos) is not merely an abstract coordinate but the actual environment in which a thing acts. Aquinas inherited the Aristotelian view that the heavens encompass the sublunary world, and the contemporary recovery of natural-kind realism preserves the underlying intuition that material substances are essentially three-dimensional, locally situated, and intelligible only in relation to other substances they encounter. The locality of space matters for Aristotelian ethics as well: the polis is the spatial unit within which the political animal pursues eudaimonia, and practical wisdom requires familiarity with the particular circumstances of the places one inhabits.

Substances are real, ontologically primary composites of form and matter. Each kind of substance has a nature (a form) that grounds its characteristic activities and natural end.

Human persons are rational animals — irreducibly embodied, social, and oriented toward eudaimonia. The flourishing of a person is the activity of the soul in accordance with virtue over a complete life.

Energy in the Aristotelian tradition is energeia — actuality, the being-at-work of a substance realising its nature — and the closely related entelecheia, having one's end in oneself. The modern physicist's energy is a distant descendant of this concept, and Aristotelians from Aquinas through contemporary neo-Aristotelians have argued that the natural-scientific quantity is intelligible only against the deeper background of activities and powers that the original Greek term names. Energy is therefore real and substantival, finite within any individual substance, and conserved in the sense that the natural ends of substances are stable features of the world. Dispersibility is registered, but the deeper Aristotelian thought is teleological: energetic processes are directed toward characteristic actualisations, not merely toward the dispersal of order.

Information in the Aristotelian tradition is essentially the in-formation of matter by form: the substantial form of an oak makes its matter an oak rather than mere wood, and the rational soul is the form of the human body. This is not information in Shannon's sense but in the older sense the English word preserves — the active principle that organises a substance and makes it the kind of thing it is. Aquinas's reception of Aristotelian hylomorphism, and the contemporary neo-Aristotelian recovery of substantial form by Lowe, Oderberg, and others, take information as relational and continuous: forms are intelligible structures, not discrete data, and they unite knower and known in the act of understanding. The intellect, on this account, becomes formally identical with what it knows.