''Actus primus'', or first actuality, is a technical expression used in
scholastic philosophy
Scholasticism was a medieval school of philosophy that employed a critical organic method of philosophical analysis predicated upon the Aristotelian 10 Categories. Christian scholasticism emerged within the monastic schools that translate ...
.
The
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
word ''actus'' means determination, complement. In every being there are many actualities, which are subordinated. Thus existence supposes
essence
Essence ( la, essentia) is a polysemic term, used in philosophy and theology as a designation for the property or set of properties that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it ...
; power supposes
existence
Existence is the ability of an entity to interact with reality. In philosophy, it refers to the ontology, ontological Property (philosophy), property of being.
Etymology
The term ''existence'' comes from Old French ''existence'', from Medieval ...
; action supposes faculty. The first actuality (''actus primus'') begins a series; it supposes
no other actuality preceding it in the same series, but calls for a further complement, namely, the second actuality (''actus secundus'').
[
But as the same reality may be called "actuality" when viewed in the light of what precedes, and "potentiality" when viewed in the light of what follows (see '']actus et potentia
In philosophy, potentiality and actuality 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''.
The c ...
''), the meaning of the term "first actuality" may vary according to the view one takes, and the point where the series is made to begin. Primary matter (see matter and form
Hylomorphism (also hylemorphism) is a philosophy, philosophical theory developed by Aristotle, which conceives every physical entity or being (''ousia'') as a compound of matter (potency) and Substantial form, immaterial form (act), with the gener ...
) is a pure potentiality, and the substantial form is its first determination, its first actuality. The complete substance
Substance may refer to:
* Matter, anything that has mass and takes up space
Chemistry
* Chemical substance, a material with a definite chemical composition
* Drug substance
** Substance abuse, drug-related healthcare and social policy diagnosis ...
constituted by these two principles receives further determinations, which are, in that respect, second actualities. Yet these may also be conceived as first actualities. Thus the extensive quantity
Physical properties of materials and systems can often be categorized as being either intensive or extensive, according to how the property changes when the size (or extent) of the system changes. According to IUPAC, an intensive quantity is one ...
of a substance is a first actuality when compared to the shape
A shape or figure is a graphics, graphical representation of an object or its external boundary, outline, or external Surface (mathematics), surface, as opposed to other properties such as color, Surface texture, texture, or material type.
A pl ...
. Power is a first actuality when compared to action.[
And this is the most frequent application of the terms ''actus primus'' and ''actus secundus''. The former is the faculty; the latter, the exercise or function. To see ''in actu primo'' simply means to have the sense of vision; to see ''in actu secundo'' is to actually perform acts of vision. The modern distinction of ]potential
Potential generally refers to a currently unrealized ability. The term is used in a wide variety of fields, from physics to the social sciences to indicate things that are in a state where they are able to change in ways ranging from the simple re ...
and kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its accele ...
might serve as another illustration: the loaded gun, or the engine with steam buildup, represent first actualities; the bullet speeding to the mark, the engine flying over the rails, represent second actualities.[
]
See also
*''Actus Purus
In scholastic philosophy, ''Actus Purus'' (English: "Pure Actuality," "Pure Act") is the absolute perfection of God.
Overview
Created beings have potentiality that is not actuality, imperfections as well as perfection. Only God is simultaneously ...
''
*''Actus Essendi
''Actus essendi'' is a Latin expression coined by Saint Thomas Aquinas (1225–1274). Translated as "act of being", the is a fundamental metaphysical principle discovered by Aquinas when he was systematizing the Christian Neoplatonic interpretat ...
''
References
Scholasticism
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