Aristotle's concept of Potency and Acts
Introduction
Potentiality and actuality are important terms and
principles Aristotle used to
analyze motion, causality, ethics, and physiology in
his Physics, Metaphysics, Nicomachean Ethics and De
Anima, which is about the human psyche.[1]
In this paper, we shall discuss in details the concept of Aristotles
potentiality and actuality. To achieve this, we shall discuss the etymology of
the terms, history, definition, division of act and division of potency,
relationship between act and potency, and then a final conclusion.
Etymology
Potentiality and potency are
translations of the Ancient Greek word dunamis as
it is used by Aristotle as a concept contrasting with actuality. Its Latin translation
is "potentia", root of
the English word potential. Dunamis is an ordinary Greek word for
possibility or capability. Depending on context, it could be translated
potency, potential, capacity, ability, power, capability, strength, possibility,
force and is the root of modern English words
dynamic, dynamite, and dynamo.[2]
Actuality is often used to translate both energeia and entelecheia.
"Actuality" comes from Latin actualitas and is a
traditional translation, but its normal meaning in Latin is "anything
which is currently happening".[3]
History
Prior
to the doctrine of act and potency, there were two great errors concerning the
problem of change and stability in beings: the static monism of Parmenides and
the philosophy of becoming of Heraclitus.
Parmenides
was the first formulator of the principle of non-contradiction, he denied the
possibility of motion or change in the world, adopting a monistic conception of
the world. Parmenides of Elea and the Eleatic school held that A thing either
is or is not. If it is, it is being; if it is not, it is nonbeing or nothing. That
which comes to be, before the change either is or is not. If it is, it is
being; if it is not, it is non-being. But we cannot say that before the change
it is; for this would mean that it comes to be what it is already, that being comes
to be being. Obviously a thing cannot come to be what it already is. On the
other hand, it is equally impossible that what comes to be is not before the
change; for this would mean that non-being comes to be, that non-being becomes
being. But it is clear that non-being cannot come to be being. Hence, Parmenides concluded that change or becoming
is positively[4]
unintelligible
and therefore impossible. Concerning the changes, we see around us, Parmenides
held that: since change is impossible, our senses deceive us when they testify
to the reality of change; for reason clearly shows that all change is a contradiction
in terms. It follows that all reality is but one being. For whatever is different
has to differ either by being or by non-being; now what differs by non-being or
nothing is not different; while on the other hand things cannot differ by being
because being is precisely that by which they are the same. In this way
Parmenides was led to static monism – monism, because he admitted
the existence of only one thing; static, because he denied that this one
thing was subject to any change whatsoever. [5]
Heraclitus,
affirmed that only change was real, stability was an illusion, there being no
fixed natures or essences in things, everything being in a constant flux; there
are no stable beings but only change or becoming. He held that reality is not
being but becoming or change. Whatever seems to be is nothing but a deception,
just as a stream may seem to be always the same, but in reality is always
changing.[6]
Aristotle’s Act and
Potency
Aristotle
arrived at a solution to the Parmenidean and Heraclitean errors concerning
change and stability in beings with his doctrine of act and potency. With
Parmenides, Aristotle maintained that being is real, and with Heraclitus, he asserted
that change is real. Being, he says, ‘is distinguished in respect of potency
and complete reality. In other words, Aristotle admits that there is a middle
ground, not between being and non-being, but between being-in-act and
non-being, and this middle ground is called being-in-potency.[7]
Thus
when we say that a thing comes to be, this does not mean that non-being becomes
being, but merely that being-in-potency becomes being-in-act, and this does not
imply any contradiction. Therefore, being and change are both intelligible, and
there is no reason to reject the reality of either. Unlike the view of
Parmenides, the change or motion that we see around us is definitely real; it
is the passage from being in potency to being in actuality. It is the
successive actualization of the potency. For example, hot water is in a state
of actuality and cold water is in a state of potentiality towards being hot water.
[8]
Potency is the capacity to have a perfection while
act is the perfection which a subject possesses. Act is contrasted to
potency, which is the potentiality to receive the perfection or act. Potency
and act are directly known through experience as correlative to each other. In
the case of potency its very constitution is to be directed towards some type
of act. [9]
potency may be described
by means of its relationship to act as the capacity for an act. While, as a matter of fact, it is true that
most acts presuppose potency, this is not so because they are acts, but because
they are limited acts. Act as act merely implies perfection, and not that this
perfection is limited.[10]
Act
and potency are considered under two aspects, namely, the physical and
the metaphysical. Regarding the physical aspect, act and potency
form the elements that make change or motion understandable. Here, what is
actual cannot be at the same time potential and vice versa. Hot water cannot be
cold water at the same time and in the same respect. Change is the transition
between being in potentiality and being in actuality.[11]
Regarding
the metaphysical aspect, act and potency form the stable constituent
principles of all finite beings, so much so that the potency, even after having
been made actual, continues to be a co-principle of its corresponding act. [12]
Potency
is that which can receive an act or already has it. This statement implies a number
of things:
·
potency is distinct from
act
·
act and potency are not
complete realities but rather principles or aspects found in things
·
potency is to act as the
imperfect is to the perfect
·
in itself, potency is not
a mere privation of act but is a real capacity for perfection.
1.
Potency is Really Distinct from Act. potency is characterized as being
the capacity to have an act or by being a receptive subject, and is therefore
distinct from act. “The constituent principles of a reality which are called
potency and act must be really distinct. For that which perfects cannot be
really the same as that which is perfectible; otherwise the perfectible would
give itself an act which it does not have, so that being would come from
non-being. Moreover, if potency and act were not really distinct, that which
limits and that which is limited would be really the same, so that act would
limit itself.[13]
2.
Act and Potecy are Not Complete Realities but Rather Principles or Aspects
Found in Things. Act and potency are the distinct co-principles of a finite
thing. Potency and act are not “things” since they are not fully constituted
entities with an independent status of their own; rather, they are the
intrinsic principles of a finite being, intrinsic co-principles which we find
in things, the intrinsic principles of being which, in union with each other,
constitute or comprise finite beings. Therefore, we affirm that potency and act
so divide being that whatever exists is either pure act (God), or is
necessarily composed of potency and act as its first intrinsic principles
(which is the case with all finite beings).[14]
3.
Potency is to Act as the Imperfect is to the Perfect. act means perfection,
a completion, something determinate. Potency, on the other hand, is an
imperfection, a capacity for perfection. The fully finished marble statue of St. Dominic is something determinate, a
perfection, something in act, while the shapeless block of marble that was the
initial material that was used for the statue would be the determinable, the imperfect,
the potency, the potentiality for perfection.[15]
4.
In Itself Potency is not a Mere Privation of Act but a Real Capacity for
Perfection. The external sense of sight, when not in use, is not a mere
privation, but is at that very moment potentially capable of being actualized
by the actual operation of seeing, which is a perfection.[16]
Division
of Potency
The
fundamental division of real potency is between passive potency and active
potency. Passive potency is the capacity a thing has to be changed
by another as other, while active potency is the power to effect a
change in another as other.[17]
Passive
potency is the capacity to receive, while active potency is the capacity to act
or do, the power to act or do. Passive potency is the capacity of a thing to be
changed by another, while active potency is the principle of activity in an
agent. Passive potency is a receptive potency, a capacity or principle which
can be acted upon, while active potency is a power or principle of action, such
as the power of sight or the power of hearing.[18]
1. Active
Potency. As examples of active potency, consider
the capacity that a man has for sensing, thinking, or willing. Capacities of
this sort (usually designated as powers) share partly in the nature of potency
and partly in the nature of act. Inasmuch as a power or a faculty is itself a
certain kind of perfection it may be designated as an act. Thus the capacity
that a man has to think and reason is in a limited sense an act. However, if we
compare the power itself – that is, as a mere capacity for doing something –
with the actual exercise of that power, we are then entitled to speak of it as
an active potency, because the mere possession of that power is not the same
as its actual use. It is from this latter point of view, then, that a power is
characterized as ‘potency.’[19]
2. Passive
potency is the capacity for receiving an act. We have entitative potency and
potency in the order of form.[20]
·
Entitative Potency.
In all finite things the act of being is a received act. The recipient
principle of this act – that is, the principle which receives it – is what we
call ‘entitative’ potency. [21]
·
Potency in the order of
form. Corresponding to the two types of act in
the order of form there are also two kinds of potency: (i) Potency for
receiving a substantial form. this is primary matter which is pure
passive potency; (ii) Potency for receiving an accidental form. This
latter is the potency in an already existing subject for receiving any act that
is ‘superadded’ to its nature or essence. A diamond, for example, is in potency
for being cut (to various shapes and sizes) by a jeweler.[22]
The
metaphysical character of potency as a capacity to receive an act pertains to
passive potency. However, it is not a homogeneous reality, but one which is
found at different levels.[23]
We can distinguish three basic types of passive potency and their corresponding
acts:
a) prime
matter and substantial form. In bodily substances
there is an ultimate substratum, prime matter, in which substantial form is
received. This form determines the matter, and thereby forms one or another
type of corporeal substance, such as iron, water or oxygen. Prime matter is the
ultimate potential substratum, since it is of itself pure potency, a merely
receptive subject which lacks any actuality of its own. The substantial form is
the first act which prime matter receives.[24]
b) substance
and accidents. All substances, whether material or
purely spiritual, are subjects of accidental perfections, such as qualities or relations.
Unlike prime matter, the substance is a subject which is already in act through
the form, but which is of itself in potency with respect to the accidents.[25]
c) essence
and act of being. The form, in turn, whether it is received in matter or
not, is no more than a determinate measure of participation in the act of
being. The essences ‘man,’ ‘dog,’ ‘pine tree,’ and ‘uranium,’ for instance, are
different ways of participating in being. With respect to the act of being,
everything is a limiting receptive potency – from the separated forms, to the
composite of matter and form, down to the accidents (which participate in the
act of being through their union with the substance).[26]
Division
of Act
Pure
Act and Mixed Act. Pure act in the
absolute sense is act which admits of no potentiality in any order whatsoever.
Such an act would neither be a co-principle united to a limiting potency nor
would it be in potency to any act of a superior order. Pure act in the absolute
sense is God Himself, Who is Pure Act of Being. [27]
Mixed
act is act which is received into potency, or
it is act which is in potency to act of another order. Mixed act is either entitative
or formal.[28]
Entitative
act is the very act of being of a finite thing. Entitative act is a mixed act
inasmuch as it is received into a potency which limits it, not inasmuch as it
is in potency to further act, for esse is the ultimate act.[29]
Formal
act, the act of essence, act in the order of essence, is the act by which a
thing is determined and perfected in its species; e.g., substantial form.[30]
First
Act and Second Act. Formal act may be
understood as either first formal act or as second formal act First formal
act is act which does not presuppose an anterior act, but awaits a
subsequent act; e.g., substantial form.[31]
Second
formal act, on the other hand, is act which
presupposes an anterior act; e.g., an accident. Therefore, second act is
accidental act. Kreyche explains that by ‘formal’ act, or ‘act in the order of
form’ we mean any act which causes a thing, not simply to be, but to be
specified according to one or another of the determinate modes of being.
Formal act may be taken in one of the two following senses: a) First formal
act. By first formal act, we mean one which determines or specifies a thing
according to its essence or nature. It is that act by virtue of which a thing
is one kind of being rather than another (for example, a rabbit rather
than a horse). The first formal act of material things is their substantial
form ; b) Second Formal Act. By second formal act, we mean any act
that is a further modification or determination of an already existing subject.
The addition of a second formal act, though it genuinely affects its subject,
does not in any way change the nature of the subject that it modifies. Thus any
accidental perfection that a thing has (such as, say the sharpness of an
alligator’s teeth) is related to it (in our example, the alligator), as a
second formal act.[32]
The
Relation Between Act and Potency as Constitutive Principles of Being
Regarding
the relation between act and potency as principles of being, we can state the
following:
·
Potency is the subject in
which the act is received
·
Act is limited by the
potency which receives it
·
Act is multiplied through
potency
·
Act is related to potency
as that which is participated to the participant
·
The act-potency
composition does not destroy the substantial unity of being.
1.
Potency is the Subject in which the Act is Received. We look at a man,
for example, and begin to know his various perfections (acts), like the color
of his hair, eyes and skin, without ever denying that these perfections reside
in that person (potency), who is the subject of these perfections (acts).[33]
2.
Act is Limited by the Potency which Receives It. Every act received in a
subject is limited by the capacity of that subject. The perfection of redness
in an apple is limited by the substance apple, its recipient. An apple can only
contain as much redness as the dimensions of that fruit allow. Unreceived act
is in itself unlimited, and when one finds limited instances of act, it is
because of a potency which receives and limits it.[34]
3.
Act is Multiplied Through Potency. The same act can be present in many
individuals which can receive it, as for example, when the specific perfection
“apple” is possessed by many individual apples because it is present in a
potency, namely, prime matter. The same substantial form is multiplied in many
individuals of the same species. Accidents (acts) are also multiplied by their
respective potencies, namely substances. The accident “red,” for example, is
multiplied insofar as there are many objects having that same color.[35]
4.
Act is Related to Potency as that Which is Participated to the Participant.
The doctrine of act and potency can be understood using the theory of
participation. To participate means to have something in part or something in a
partial manner. This presupposes that there are other subjects that possess the
same perfection, none of them possessing that said perfection in full.[36]
Also,
in participation, the subject cannot be identical to what it possesses; the
subject merely possesses this perfection by participation only. The subject of
participation has the perfection, possesses the perfection; he is not the
perfection, he doesn’t have the perfection by essence, that is, in a full and
exclusive manner, by being identical with it. Creatures have the act of being while
God is the Act of Being by Essence, that is, Essence and Act of Being are
identical in the Divine Being. Now, while pure actuality is act by essence, the
relationship of act and potency is one of participation. The subject (potency)
capable of receiving a perfection (act) is the participant, and the act itself
is that which is participated in by the subject.[37]
5.
The Act-Potency Composition does not Destroy the Substantial Unity of a
Being. Act and potency are not subsistent beings in themselves but rather
constituent principles of finite beings. They are not things but rather the
co-principles of a thing. Potency is by nature a capacity for perfection, a
capacity towards an act, to which it is essentially ordered and without which
it would not be able to exist at all (prime matter [potency], for example,
exists for the form [act], without which it simply would not exist). Potency’s
union with its act cannot therefore give rise to two individual things, two separate
beings.[38]
Conclusion
So
far, we have been able to discuss in details the basics of Aristotle’s act and
potency. From the discussion, it is obvious that Aristotle brought about those
concepts to solve the problems and errors of change and static which has been
in existence. Aristotle did not only address the errors but also made important
input in philosophy.
REFERENCE
Primary
source:
Paul Gerard Horrigan, Ph.D, Act And
Potency 2009.
Secondary sources
Aristotle on
Science The Posterior Analytics. Proceedings
of the eight symposium aristotelicum held in padua from semtember 7 to 15,
1978. Edited by Enrico Berti
ARISTOTLE, Metaphysics,
IX, 1, 1045b 34.
C. A. HART, Participation
and the Thomistic Five Ways, “The New Scholasticism,” 26 (1952), pp. 267-282
H.
J. KOREN, Introduction to the Science of Metaphysics, B. Herder, St.
Louis, 1965, pp. 105-106.
W.D. Ross,
Aristotles’s Physics. A revised text with introduction and
commentary. oxford at the clarendon press. 1936
Internet
sources
[5] H. J.
KOREN, Introduction to the Science of Metaphysics, B. Herder, St.
Louis, 1965, pp. 105-106.
[6] H. J. KOREN, Introduction to the Science of Metaphysics, B. Herder, St. Louis, 1965, pp. 105-106.
[10] ibid
[11] ibid
[12] ibid
[14] ibid
[15] ibid
[16] ibid
[17] R. P. PHILLIPS, Modern Thomisic Philosophy,
vol. 2 (Metaphysics), Newman, Westminster, MD,1935, pp. 180-181.
[19] ibid
[20] ibid
[23] ibid
[24] ibid
[25] ibid
[26] ibid
[28] ibid
[30] ibid
[31] ibid
[32] ibid
[34] ibid
[35] ibid
[37] C. A. HART,
Participation and the Thomistic Five Ways, “The New
Scholasticism,” 26 (1952), pp. 267-282
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