The movement
Chapter 1
Aristotle, from potential to action
We’re going to explore a key thought in the concept of movement: Aristotle.
When we think of movement, we generally imagine a displacement, a change of position in space. For Aristotle, movement, or rather ‘kinesis’ in Greek, is much more than just displacement. It encompasses all forms of change, whether growth, alteration, birth or disappearance.
Join me as we delve into the heart of the Aristotelian system, to see how Aristotle defines movement, why this concept underpins his vision of nature, and how it fits into his metaphysics, physics and cosmology.
Let’s set off together to discover Aristotle’s thinking and kinesis:
Aristotle was born in Stagira in northern Greece in 384 BC. He studied under Plato at the Academy of Athens, before leaving to found his own school.
While Plato believed that the sensible world was merely an imperfect copy of the eternal and unchanging Ideas, Aristotle was primarily interested in the concrete world of nature, living beings and the objects that surround us. He was an empirical philosopher who observed, classified and dissected reality.
From this perspective, movement – the transformation of things – was central to him. For Aristotle, understanding the world meant understanding why and how things change, pass from one state to another, acquire a form, quality or quantity, or move through space. Movement becomes the heart of his philosophical system, the link between being said to be in potential and being said to be in act.
The Greek word for ‘movement’ is ‘kinesis’. But in Aristotle, kinesis is not, as we said earlier, reduced to spatial translation. Movement is defined as the passage from power to act. What does this mean? It means that movement is the process by which something that has a potential within it – a ‘power’ – is realised in an actual state.
To give a concrete example, an acorn is potentially an oak tree. The tree is not yet there, but the potential of an oak is contained in this acorn. The process of growth and development, the transformation from acorn to sapling to adult tree, is movement in the Aristotelian sense. Change is therefore much broader than mere displacement: it is any transition from a potential state to an actual state.
Aristotle classifies several types of movement:
- Quantitative movement, such as the growth or reduction of a living being. In short, the acorn that becomes an oak tree.
- Qualitative movement, such as a change in colour or shape, or the transformation of a substance under the effect of heat or cold. For example, the leaves of an oak tree change from green to red in autumn.
- Local movement, i.e. movement in space, like an animal walking or an object being thrown. In short, the acorn falling from the oak
- Generation and corruption, i.e. the birth or disappearance of a being, as when a plant sprouts or a flower withers and decomposes. In short, the acorn that sprouts and transforms into a young shoot to become an oak tree.
For Aristotle, all these changes are forms of movement in the broadest sense. They bear witness to the dynamism of the world, a universe in the process of becoming, where nothing is eternally fixed in the same state.
We can’t talk about movement in Aristotle without mentioning his famous concept of the First Immovable Engine.
In Aristotelian cosmology, the universe is eternal, and the stars describe perfect circular motions. To avoid regressing to infinity, i.e. the impossibility of finding an origin of things where every consequence is preceded by a cause, Aristotle postulates the existence of a prime mover, an entity that is purely ‘actual’, immutable, without any power, immaterial and therefore immobile.
This First Immobile Engine would be the ultimate final cause of all movement: it draws the universe to itself as the ultimate end, like a perfectly fulfilled object of desire. The celestial spheres, aspiring to perfection, are thus set in motion to strive for it. In this way, the movement of the universe is sustained by this first principle, without the need for it to move itself. This immobile prime mover is the guarantor of cosmic order, the ultimate source of all dynamism.
This idea enables Aristotle to articulate universal movement on a metaphysical basis: perpetual change in the sublunary world (that of the Earth, of generation and corruption) is part of a wider order, animated by the unalterable presence of this divine principle.
What is essential, in his view, is the link between movement and potentiality. Movement is not a marginal accident, an imperfection, as Plato thought; it is at the very heart of being, because everything has potentialities within it that seek to be fulfilled, to be actualised. Movement is therefore a fundamental principle of actualisation, the way in which what is in germ becomes fully what it is destined to be.
To explain movement, Aristotle uses his theory of the four causes :
• The material cause : the matter from which something is made.
• The formal cause : the form or essence that defines the thing.
• The efficient cause : the agent or principle that produces change.
• And the final cause : the goal or end towards which the process tends.
Movement, as the passage from power to act, presupposes that there is an efficient cause that initiates the change, as well as a final cause that directs the process towards a goal. For example, the acorn becomes an oak tree not only because it has the power to be one, but also because the conditions (soil, water, light) and its essence push it to actualise its potential, and because there is a natural end, an accomplished state towards which it tends, being an oak tree.
In this Aristotelian way of thinking, movement is not only a fact, it is also teleological, directed towards a goal. It is not chaos or pure chance, but a structured process.
To better understand Aristotle, it is interesting to compare him with his master Plato. Plato believed in a perfect, eternal and unchanging intelligible world, and saw the sensible world as a realm of imperfect copies, subject to change. Movement was seen as a sign of imperfection.
Aristotle, on the other hand, embraced the reality of movement: he normalised it, theorised it, and placed it at the centre of nature. Far from being a defect, movement is the very condition of the actualisation of beings, of their perfection. Perfect stability belongs to the First Immobile Engine, but the rest of the cosmos is naturally in motion, without this being a metaphysical problem. On the contrary, it is the normal order of things.
Aristotle’s concept of movement is therefore much richer than we might imagine from our common sense. It is not just a question of changing place, but of any transition, any realisation of a potential. Movement thus becomes one of the fundamental principles of Aristotle’s thought, linking metaphysics, physics, biology, cosmology and even theology.
Whether it’s an acorn becoming an oak, an animal growing, the colour of a piece of fruit ripening, or the stars revolving in the sky, all movement is understood as a passage from power to action, directed towards an end and supported by causes. Aristotle’s world is a living, dynamic universe in which movement is both an observable fact and a philosophical principle, linking nature and thought.