Potentiality and actuality

In philosophy, Potentiality and Actuality are principles of an important dichotomy used extensively by Aristotle to analyze time, motion, causality, biological perfections and human faculties in his Physics, Metaphysics and Ethics.

In broad terms, potentiality is a capacity or possibility, and actuality is its exercise or fulfillment.

Being is said in many ways

Being, in ancient Greek to on, the present participle of the verb "to be" einai, is studied both in modern metaphysics and in ontology, to which it gave its name. According to Aristotle, it has many senses, and it can be studied by many sciences in its numerous aspects. In his lecture notes, Metaphysics, Aristotle makes the following divisions:

• Being as katà symbebekós (per accidens) and being as kath' autó (per se).
• Being as true or false.
• Being as a substance, in particular, or as the differentia of genus and species.
• Being as potentiality or possibility, dýnamis, and as actuality, enérgeia or entelécheia.

The first distinction deals with being as an unnecessary coincidence: for example, Socrates being musical. It is not necessary for Socrates to be musical. It is therefore something said to be by accident, per accidens, when a subject has a property which is not a logical necessity for the subject to either lack or possess.

Being as true and false corresponds to the relation between expressed opinion, doxa, and what is real. If someone says a white wall is red, and what they've said does not justified in reality, (the wall is not red), then what they've said is false. If the wall is indeed red, then what they've said is true.

Being as a substance, ousia, refers to a particular being as the ultimate subject of predication. Accidents are always predicated of a particular: musical, for example, is predicated of Socrates, not of musical man.

Aristotle describes potentiality and actuality, or potency and action, as another kind of way in which a thing is said to be. However, unlike the other three, this kind can be said regarding a substance, a truth, a fallacy or of accidental properties. Potentiality refers to what has not yet come to be; and actuality refers to what has come to be and still is.

Potentiality as distinct from actuality

Aristotle argued against the Megarics, who claimed that one can only have a potentiality when one is actually exercising whatever action is referenced by it. Aristotle characterized such a view as absurd: a person who is a builder, for example, is called a builder because they've learned to build (a skill one doesn't normally forget). However, they would lose that ability after a building is built; and having lost the ability, as opposed to the knowledge, they would not be able to build again to supposedly regain the ability. Equating possibility with actuality makes all movement and processes of change impossible because even the simplest actions, like sitting down, would be impossible for those who are standing (as would standing up, for those who are seated).

One may be capable (dunamis) of some action without actually being engaged in doing so. Similarly for other categories, possibility can always be said of a subject, unless it would be impossible for a thing, as such, to actually move like so, or to actually be moved like so. Thus, anyone can always do anything people do, albeit well or poorly, circumstances permitting and provided one has learned, (if necessary, and remembers how), unless permanently disabled or temporarily incapacitated. As for anything not said to move (or be moved) in reality, such things do not exist; they are just the stuff of imagination, or desire, and of those that are realistically possible, such things have the potential to come to be.

Temporally, a potentiality must precede its actuality. Logically however, a potentiality is posterior to the actuality on which it depends, and so the actuality must not be impossible. The actuality of a potentiality must be logically consistent, in all ways, with some sense of reality.

Actuality and action

Template:The Works of Aristotle

Further information: Energeia and Entelechy

Actuality, in Greek ἐνέργεια (energeia) and in Latin actus, means activity, (act, action, actuality), operation, vigor, workmanship, perfection, determination, force.

Entelechy, in Greek ἐντελέχεια (entelécheia, from telos: "end" or entelēs: "complete" and echein: "to have") and in Latin entelechia, is an actual instance (a substance), used interchangeably with engergeia, often regarding the soul, a complex hylomorphic substance. Later, Neoplatonic commentary would syncretize this with possibility (dunamis). It is the condition of something whose essence is fully realized; actuality. In some modern philosophical systems it is a vital force that motivates and guides an organism toward self–fulfillment. According to David Bradshaw, both energeia and entelécheia were neologisms coined by Aristotle: "For the ergon is the telos, and the energeia is the ergon, therefore the word energeia derives from ergon, and points toward complete reality." See also, the etymology of ἔργον, (ergon: "work").

Potentiality and possibility

Main article: Dunamis

Potentiality, in Greek δύναμις (dunamis) and in Latin potentia, means power, potency, capacity, capability, skill, faculty, influence, value, worth, or in mathematics: square root and power. In Aristotle's philosophy of hylomorphism, it is often used in connection with matter or substance, as opposed to form, and sometimes takes on the meaning possibility as later developed in modal logic. It is possible in some texts to find an account of possibility which suggests that Aristotle has in mind a different form of potentiality. However, the texts are not clear enough, and many interpretations have been given to them. One could, for example, read the following passages: Metaphysics Θ 3, 1047a 24; Θ 6, 1048a 28-30; De Interpretatione 23a 8-16. In this last text Aristotle states that this potentiality corresponds not only to mobile being, but also to eternal beings (that is, beings outside the range of kinesis).

What follows is only a possible way of accounting for the different meanings of potency in Aristotle. The distinction is made according to the Greek terms:

1. Potency in the order of reality: dynatón.
   • dynatòn katà dýnamin: everything that is possible;
   • ón dynámei: the being that simply has a potentiality (which can be active or passive);
   • dynatòn katà tò télos: the same real potency according to its goal.
2. Potentiality in the logical order: dynatà oú katà dýnamin.

Later, the notion of possibility will be greatly analyzed by medieval and modern philosophers. Indeed, many philosophical interpretations of possibility are related to a famous passage on Aristotle's On Interpretation, concerning the truth of the statement: "There will be a sea battle tomorrow".

Contemporary philosophy regards possibility, as studied by modal metaphysics, to be an aspect of modal logic.

Some philosophers claim that actuality refers to the act of knowledge (the third sense of act); the transitive act would not be an actuality but, rather, an activity or action.

Common sense

Main article: Sensus communis

Aristotle uses many different words that signify different aspects of the formal action. For example: tode ti, to ti en einai, eidos, morphe, ti esti, sxema, etc. Normally, morphe is understood as the generic name of the hylomorphic form; if a particular morphe is the one that most determines a substance (ousía), it is understood as the essence or essential form (tode ti, to ti en einai). The word eidos (idea, a synonym for form), may sometimes refer to the intellectual apprehension of form. The term is taken from Plato's forms (eide: idea).

Common sense, in Greek κοινὴαἲσθησις (koinē aisthēsis) and in Latin sensus communis, refers to the perception of sensory phenomena, as per the common opinion (doxa) of reasonably competent observers.

An internal sense, formerly believed to be the sense by which information from the other five senses is understood and interpreted.

This common sense is the judge or moderator of the rest, by whom we discern all differences of objects; for by mine eye I do not know that I see, or by mine ear that I hear, but by my common sense...

Actuality means the fulfillment of a capacity and potentiality refers to something in the future actuality, which at present exists only as a germ to be evolved, (actuality denoting the corresponding complete reality). Potentiality is the determinable being and actuality is the determined being.

In Aristotelian psychology, (which is applicable to all animals), special emphasis is laid on the reality of potentiae, or faculties, and their distinction both from the soul and from their operations. External senses are determined or actualized by an external stimulus, which gives them the determination necessary to the act of perception. The internal senses (sensus communis, phantasia, memoria, aestimativa) depend on external sensations for their exercise. Memory and imagination preserve in potentia traces of past impressions, and when the proper conditions are verified the image becomes actual. One has no innate ideas in the beginning, one has the power to acquire ideas.

Bibliography

• Bradshaw, David (2004). Aristotle East and West: Metaphysics and the Division of Christendom. Cambridge University Press. ISBN 9780521828659.
• Burton, Robert (2001). The Anatomy of Melancholy [1621]. Vol. Book I. New York.{{cite book}}: CS1 maint: location missing publisher (link)
• Durrant, Michael (1993). Aristotle's De Anima in Focus. Taylor & Francis. ISBN 9780415053402.
• Smith, J.A. trans. (2009). "The Internet Classics Archive – Aristotle On the Soul". MIT.
• Edghill, E.M. trans. (2009). "The Internet Classics Archive – Aristotle Categories". MIT.
• Hardie, R.P. & Gaye, R.K. trans. (2009). "The Internet Classics Archive – Aristotle Physics". MIT.{{cite web}}: CS1 maint: multiple names: authors list (link)
• Tredennick, Hugh trans. (1989). "Metaphysics". Aristotle in 23 Volumes. Vol. 17, 18. Cambridge: Harvard University Press; (London: William Heinemann Ltd. [1933]).

• Ross, W.D.; Smith, J.A. (1908). Metaphysica. The Works of Aristotle. Vol. VIII. Oxford: Clarendon Press.
• Warnock, Mary (1950). "A Note on Aristotle: Categories 6a 15". Mind. New Series (59).

See also

• Actual infinity
• Dunamis
• Energeia
• First cause
• Hylomorphism
• Unmoved movers

Notes and references

• Abbreviations: Categoriae Catg.
• De Anima De An.
• De Interpretatione De Int.
• Metaphysica Meta.
• Physica Phys.

References to Aristotle's works by title, book and chapter using Bekker numbers, (numerals and letters printed in the outer margin), are derived from page, column and line numbers in Bekker's 1831 edition of the Greek text. The line numbers in translations, however, do not necessarily correspond to the given line numbers in the Greek text.