Potentiality and actuality
In philosophy, potentiality and actuality[1] are a pair of closely connected principles which Aristotle used to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Nicomachean Ethics, and De Anima.[2]
"Actuality" redirects here. For the film genre, see Actuality film.
The concept of potentiality, in this context, generally refers to any "possibility" that a thing can be said to have. Aristotle did not consider all possibilities the same, and emphasized the importance of those that become real of their own accord when conditions are right and nothing stops them.[3]
Actuality, in contrast to potentiality, is the motion, change or activity that represents an exercise or fulfillment of a possibility, when a possibility becomes real in the fullest sense.[4] Both these concepts therefore reflect Aristotle's belief that events in nature are not all natural in a true sense. As he saw it, many things happen accidentally, and therefore not according to the natural purposes of things.
These concepts, in modified forms, remained very important into the Middle Ages, influencing the development of medieval theology in several ways. In modern times the dichotomy has gradually lost importance, as understandings of nature and deity have changed. However the terminology has also been adapted to new uses, as is most obvious in words like energy and dynamic. These were words first used in modern physics by the German scientist and philosopher, Gottfried Wilhelm Leibniz. Aristotle's concept of entelechy retains influence on recent concepts of biological "entelechy".
The actuality-potentiality distinction in Aristotle is a key element linked to everything in his physics and metaphysics.[23]
Aristotle describes potentiality and actuality, or potency and action, as one of several distinctions between things that exist or do not exist. In a sense, a thing that exists potentially does not exist; but, the potential does exist. And this type of distinction is expressed for several different types of being within Aristotle's categories of being. For example, from Aristotle's Metaphysics, 1017a:[24]
Within the works of Aristotle the terms energeia and entelecheia, often translated as actuality, differ from what is merely actual because they specifically presuppose that all things have a proper kind of activity or work which, if achieved, would be their proper end. Greek for end in this sense is telos, a component word in entelecheia (a work that is the proper end of a thing) and also teleology. This is an aspect of Aristotle's theory of four causes and specifically of formal cause (eidos, which Aristotle says is energeia[25]) and final cause (telos).
In essence this means that Aristotle did not see things as matter in motion only, but also proposed that all things have their own aims or ends. In other words, for Aristotle (unlike modern science), there is a distinction between things with a natural cause in the strongest sense, and things that truly happen by accident. He also distinguishes non-rational from rational potentialities (e.g. the capacity to heat and the capacity to play the flute, respectively), pointing out that the latter require desire or deliberate choice for their actualization.[26] Because of this style of reasoning, Aristotle is often referred to as having a teleology, and sometimes as having a theory of forms.
While actuality is linked by Aristotle to his concept of a formal cause, potentiality (or potency) on the other hand, is linked by Aristotle to his concepts of hylomorphic matter and material cause. Aristotle wrote for example that "matter exists potentially, because it may attain to the form; but when it exists actually, it is then in the form".[27]
Teleology is a crucial concept throughout Aristotle's philosophy.[28] This means that as well as its central role in his physics and metaphysics, the potentiality-actuality distinction has a significant influence on other areas of Aristotle's thought such as his ethics, biology and psychology.[29]
Post-Aristotelian usage[edit]
New meanings of energeia or energy[edit]
Already in Aristotle's own works, the concept of a distinction between energeia and dunamis was used in many ways, for example to describe the way striking metaphors work,[32] or human happiness. Polybius about 150 BC, in his work the Histories uses Aristotle's word energeia in both an Aristotelian way and also to describe the "clarity and vividness" of things.[33] Diodorus Siculus in 60-30 BC used the term in a very similar way to Polybius. However, Diodorus uses the term to denote qualities unique to individuals. Using the term in ways that could translated as 'vigor' or 'energy' (in a more modern sense); for society, 'practice' or 'custom'; for a thing, 'operation' or 'working'; like vigor in action.[34]
Platonism and neoplatonism[edit]
Already in Plato it is found implicitly the notion of potency and act in his cosmological presentation of becoming (kinēsis) and forces (dunamis),[35] linked to the ordering intellect, mainly in the description of the Demiurge and the "Receptacle" in his Timaeus.[36][37] It has also been associated to the dyad of Plato's unwritten doctrines,[38] and is involved in the question of being and non-being since from the pre-socratics,[39] as in Heraclitus's mobilism and Parmenides' immobilism. The mythological concept of primordial Chaos is also classically associated with a disordered prime matter (see also prima materia), which, being passive and full of potentialities, would be ordered in actual forms, as can be seen in Neoplatonism, especially in Plutarch, Plotinus, and among the Church Fathers,[39] and the subsequent medieval and Renaissance philosophy, as in Ramon Lllull's Book of Chaos[40] and John Milton's Paradise Lost.[41]
Plotinus was a late classical pagan philosopher and theologian whose monotheistic re-workings of Plato and Aristotle were influential amongst early Christian theologians. In his Enneads he sought to reconcile ideas of Aristotle and Plato together with a form of monotheism, that used three fundamental metaphysical principles, which were conceived of in terms consistent with Aristotle's energeia/dunamis dichotomy, and one interpretation of his concept of the Active Intellect (discussed above):-