[Note: As July
quickly approaches, I will not be making many posts on this blog. I
will have my two beautiful daughters with me for the month and much
of my time will be spent with my family. These are the times I
rediscover that love is the primary matter which holds our family
together.]
At any rate, here are some initial and unfinished thoughts regarding physics and metaphysics. The more I delve into the concept of Being, the further I seem to go into the philosophy of science and the existential import of what it means to be and become in this temporal world. I remain impressed by how the classical categories of Western thought (specifically, act and potency, accepted by both neo-Platonists and Aristotelians) hold up and have stood the test of time.
Part two of my essay on Heisenberg’s appeal to Aristotelian metaphysics can be found here.
I probably won’t
be able to explicate these further until August, but here are a few
rough and undeveloped reflections that came to me when thinking about
the intersection of science and the philosophical first principles of
reality. Post below if you have anything to add or something which
you think needs further discussion.
1. The Copenhagen
School interpretation of quantum mechanics seems to indicate that we
can say nothing about the properties of an atom or sub-atomic
particles. All scientists can do is provide the results of
experiments on them. Would it be better to say that the strange
behavior of quantum mechanics demonstrates the classical nature of
potential waiting to be put into act? Perhaps that is the nature or
essence of quantum physics?
2. The mystery of
causality. Predictability in the quantum realm may not hold in
particular cases. That does not mean, however, that there is no
efficient cause or sufficient reason for its action. An efficient
cause may be unpredictable but that does not mean it does not exist.
3. The actual world
we live in is alive with potentialities from the smallest elements of
matter to human individuals. This is what we mean when we speak of
“human potential.” Our world is charged with real
potentialities, relationships, and interactions between real beings.
4. Many of the early scientists and mathematicians working on quantum phenomena such as Planck, Heisenberg, and Bohr were not strict materialists. Neither were other influential thinkers of the time such as Bergson, Einstein, Whitehead, and Hardy. They all understood that something more is going on in our world than matter, energy, and motion. In other words, they would have rejected the undue and uncritical acceptance of the scientific method as it is applied to every other field of inquiry such as philosophy, history, or the humanities.
5. Perhaps
Einstein’s formula regarding the convertibility of matter and
energy (Energy = the mass x the speed of light squared), points to
Aristotle’s “primary matter”? (It may of itself have no form
but must always be structured by some form or essence?)
6. The classic question of the one and many. Heraclitus was only half correct when he stated that all reality is in flux. Our world is not in total or complete flow or chaos. Even Heisenberg’s Indeterminacy Principle is not infinite. There must be something that perdures or there would be no sense of continuity. In this regard, quantum physics point to the classical question of the one and many (which also speaks to the nature of relationships).
7. The great conversation regarding act and potency which was started by Aristotle, accepted by Plotinus, elaborated by Aquinas, and rediscovered by Heisenberg needs to be explored, developed, and integrated for our time. Metaphysics is about recovering the first principles of Being.
So what do Aristotelian-Thomist notions of act/potency and form/matter have to do with quantum dynamics? In 1975 Werner Heisenberg gave a lecture to German physicists and said, “good science is being unconsciously discarded because of bad philosophy” and sought to correct the situation with his book, Physics and Philosophy. The bad philosophy that Heisenberg wanted to redress was the materialistic, mechanistic, and deterministic view of nature assumed by Enlightenment physicists and philosophers. He specifically appealed to the metaphysics of Aristotle to correct the deterministic view of Newtonian physics. It is important to note at this point that much of Aristotle’s ideas were either thrown out or misinterpreted by early modern philosophers and scientists due to their materialist assumptions. Heisenberg’s appeal to Aristotle’s metaphysics was a bold new move for his day but he realized it made the most sense out the facts as they were presented to him.
So what was Heisenberg getting at when he explained the function of sub-atomic particles in the Aristotelian category of ‘potential’? In his book Physics and Philosophy, he tells us:
“In throwing dice we do not know the fine details of the motion of our hands which determine the fall of the dice and therefore we say that the probability for throwing a special number is just one in six. The probability wave of Bohr, Kramers, Slater, however, meant more that; it meant a tendency for something. It was a quantitative version of the old concept of “potentia” in Aristotelian philosophy. It introduced something standing in the middle between the idea of an event and the actual event, a strange kind of physical reality just in the middle between possibility and reality” (396).
According
to Heisenberg, the probability inherent in quantum behavior is
potential – a tendency for something. (This might also imply a
‘telos,’ or purpose, but we will not develop that here.)
Heisenberg is clearly stating that the many abilities, capacities,
possibilities, or dispositional properties a sub-atomic particle has
is its potential.
When explaining the unity of matter as energy or universal matter
(similar to Aristotle’s ‘prime matter”) Heisenberg says this,
“If we compare this situation with the Aristotelian concepts of
matter and form, we can say that the matter of Aristotle, which is
mere “potentia,” should be compared to our concept of energy,
which gets into “actuality” by means of the form, when the
elementary particle is created” (440). Here Heisenberg is
intuitively correct. Matter is always in potential. Contrary to
early modern philosophers such as Descartes and others, matter and
form are not so easily thrown out. Matter and form, or as Heisenberg
might say, energy as a form of matter are necessary conceptual tools
which physicists use to describe the world. Here, it is important to
note two things, the first is that potential is not empirical, the
second is that potency is not pure chaos.
First, potential is inaccessible to the strict empiricist. No
empiricist who believes that all human knowledge is restricted to
what can be observed by some sense experience can allow for potency.
Why? Because although potency can be observed through act as an
effect (in hindsight, so to speak), it can not be directly observed
by itself through sense perception. This is why no real scientist is
a strict empiricist because they are always appealing to properties,
capacities, probabilities, or capabilities of matter, even though
potential is never known by itself apart from that which is in act.
The second thing to keep in mind is that at the quantum level, the
range of probabilities (potential) is not absolutely indeterminable
or chaotic. Heisenberg’s uncertainty principle states that the
quantum mechanical behavior of sub-atomic particles is not absolutely
indeterminate because it can only oscillate between a range of
probabilistic values (Silva 638). This is why things correspond to
their nature or essence. Potency can only have an effect on a range
of possibilities to that which is in act.
Finally, Heisenberg claimed that many of his fellow physicists were
coming to the same Aristotelian conclusions, “One might perhaps
call it an objective tendency or possibility, a ‘potentia’ in the
sense of Aristotelian philosophy. In fact, I believe that the
language actually used by physicists when they speak about atomic
events produces in their minds similar notions as the concept
‘potentia.’ So the physicists have gradually become accustomed to
considering the electronic orbits, etc., not as reality but rather as
a kind of ‘potentia’” (447). Heisenberg came to realize that
many of his colleagues were beginning to understand the philosophical
implications of quantum dynamics in Aristotelian terms. This should
not be surprising since reality is the determinate of order and will
always reveal its own intractable way of being.
Max Planck, who is considered the father of quantum theory, also held
that scientific discoveries ultimately point to a metaphysical
reality. Although he did not explicitly use the category of
potential, he was very aware of the philosophical implications of
quantum mechanics. “As there is a material object behind every
sensation, so there is a metaphysical reality behind everything that
human experience shows to be real” (97). Potency seems to be the
best metaphysical category that explains the mysterious behavior of
quantum particles. It certainly cannot explain the entire mystery,
for there are still many remaining questions for science to explore
but act and potency are viable options that the physicist and
metaphysician can use to describe reality. These metaphysical
co-principles have stood the test of time and point us to the nature
of ultimate reality. In many ways, reality itself points to a
metaphysical reality. Plank went on to explain that, “Metaphysical
reality does not stand spatially behind what is given in
experience, but lies fully within it. … The essential point
is that the world of sensation is not the only world which may
conceivably exist, but that there is still another world. To be
sure, this other world is not directly accessible to us, but its
existence is indicated time and time again” (98). The metaphysical
co-principles of act/potency and form/matter help us understand what
is happening in the physical realm.
From these remarks by Planck and Heisenberg, and through an investigation of the Aristotelian categories of act and potency, we see that reality by its very nature is oriented toward self-expressive action. In classical philosophy, the physical world is seen as “one and many” or “being and becoming” (both are needed to make sense of the world). Potentiality, however, is the category used for explaining the dynamic aspect of life. Nothing in the human, animal, or plant kingdoms can grow, develop, or meet its potential by being static. To stand out of nothing—the very meaning of existence—is to be oriented toward action and is the reason there is a metaphysical basis for reality, even at the atomic level. The Aristotelian categories of act and potency account for the dynamic and changing realities we experience in the world around us. Potency itself is not a strictly empirical phenomenon but is indispensable for accounting for and maintaining the integrity of the empirical data. There are all sorts of non-empirical realities that nature itself points us to—from the smallest sub-atomic particle to human nature itself.
[Special thanks and gratitude go to my friend Dr. Derek Gardner at the University of Arizona for keeping me pointed in the right direction regarding the issues around quantum physics. Without his guidance my ontology would have certainly failed.]
Works
Cited
Heisenberg, Werner. Physics and Philosophy. Great Books of the Western World. Vol. 56. Encyclopedia Britannica, Inc., 1999
Planck, Max. Scientific Autobiography and Other Papers. Great Books of the Western World. Vol. 56. Encyclopedia Britannica, Inc., 1999
Silva, Ignacio. “Werner Heisenberg and Thomas Aquinas on Natural Indeterminism.” New Blackfriars, 2013, 635 – 653.
For
further reading:
Clarke, Norris. The One and The Many: A Contemporary Thomistic Metaphysics. University of Notre Dame, 2001.
Goetz, Stewart and Charles Taliaferro. Naturalism. Wm. B. Eerdmans Publishing, 2008.
“As there is a material object behind every sensation, so there is a metaphysical reality behind everything that human experience shows to be real.” – Max Planck, Scientific Autobiography
[Note: I would like to thank Dr. Derek Gardner for reading a draft of this essay and supplying helpful suggestions. His scholarship saved me from making errors when describing quantum mechanics and I deeply appreciate his insight.]
I recently heard a professional philosopher say that metaphysics is no longer a dirty word in the field of philosophy. This was good news to me, because for the last four hundred years or so metaphysics has been considered a lost cause in philosophy. Upon reflection, however, I think there has been a small resurgence in the interest of classical metaphysics but the philosophy of mind, language, science, politics, and ethics still seem to be the most popular areas of study in the field. I’m still told that professional positions for metaphysicians are hard to find. Nonetheless, it is fascinating that philosophy is rediscovering its primary role—to explicate the most universal principles of reality and discover the rules, axioms, and laws that make our universe, fields of learning, and human experience possible in the first place. I think the ultimate questions of reality and what it means to be human will never really go away. Thoughtful individuals will always try to offer systematic attempts to illumine our human experience in depth and set it in a vision of the whole of reality. Why might there be an emerging interest in metaphysics and what would that tell us about the relationship between philosophy and science?
Aristotle
explains in his Metaphysics that there is a science (for Aristotle
‘science’ is a body of knowledge) which is concerned with “being
as being” and that the primary causes and principles of being are
the object of study for the metaphysician. This is the formal study
of ontology, the metaphysical exploration of all existing things as
they exist, the properties of being, and whether certain things,
whose existence can be questioned, do or do not exist. Aristotle
also laid out the tactical possibilities for conducting what we now
call the physical sciences – the study of the structure and
behavior of the natural world through repeated observation and
experiment. For Aristotle, however, and the many classical and
medieval philosophers that came after him, the physical world and the
ultimate principles of reality (what they would have called ‘physic’
and ‘metaphysic’) are not to be divorced or separated because
both are needed to explain the ultimate nature and significance of
reality. While the subdivision and classification of learning and
science is helpful for sharpening one’s focus on their object of
study, most areas of study ultimately fall back on basic first
principles that attempt to explain or support their overall project,
such as the principle of sufficient reason, the law of identity, the
law of noncontradiction, correspondence, cause and effect, act and
potency among others. Perhaps one reason metaphysics is being
re-discovered is that all fields of inquiry, whether the social
sciences or physical sciences, use foundational first principles
which reflect their basic assumptions about the nature of the
universe and how the world works. Note that nearly all our basic
assumptions are not empirical in the sense used by Enlightenment
philosophers and natural scientists and yet it would be foolish to
discard them. There are many immaterial and material aspects of
reality. The union of the immaterial with the material has often
been discarded or forgotten in Western thought but recently have been
rediscovered with interesting metaphysical corollaries. Every
cosmology, mathematical formula, scientific hypothesis, and ethical
theory has metaphysical implications.
Another reason I think metaphysics is being rediscovered is that a few physicists and mathematicians in the twentieth-century ventured into the discussion and pointed out that physics and metaphysics are indeed related and ought not to be detached. This was a profound change in Western thought at least since the Enlightenment. Due to the skeptical theories of Descartes, Hume, Hobbes, and Kant, metaphysics was considered dead or impossible to pursue. However, interesting scientific developments in the early part of the twentieth-century changed things. Einstein’s colleagues, Max Planck, Werner Heisenberg, G.H. Hardy, Niels Bohr, and Erwin Schrödinger, among others, argued for a new understanding of nature due to the quantum discoveries of their day that described the behavior of reality at the atomic scale, where standard Newtonian physics failed to do so. Here, a basic tenet of quantum mechanics, as opposed to classical mechanics, is that reality, at an atomic level is not causally linear or smooth in its behavior but probabilistically discontinuous and discrete. In Newtonian physics, for instance, and in the classical “every day” large-scale sense to which it applies, it is generally possible to determine the future states of a system by knowing its present state (e.g., we can predict where a baseball will land given some initial conditions). In the new atomic physics of the twentieth century, this was no longer the case. Classical mechanics has at its basis the contention that all states of a considered system can be measured and known. When we describe atomic physics with quantum mechanics, on the contrary, one must accept that it is impossible to know the exact value of a parameter without measuring it, and one can know it only for that measurement. Heisenberg’s discovery of quantum indeterminism suggests that in the moment of an atomic measurement, the system (e.g., a molecule) is necessarily disturbed (e.g., by a probing photon) thus “collapsing” the original potential possibility-space into one state of the many probable states, some with much higher probability, but otherwise without any reason to “collapse” into one or another particular possible state (Silva, 637). The most one can do to describe the state of any given system, before or after the measurement, is to provide a probability for the outcome of that measurement (Dirac, 73).
From the
standpoint of Aristotelian philosophy, Werner Heisenberg is
especially interesting due to his specific appeal to Aristotelian
categories of act and potency when describing his theory of
indeterminism. Before getting further into Heisenberg’s
interpretation of quantum mechanics, however, it is important to
understand the central Aristotelian categories of Act and Potential.
As a quick review, ‘act’ or ‘actuality’ simply refers to that which exists. It is the physical, concrete existence of something (philosophers call this the ‘positive mode of perfection’ but we will not go into that here). For now, think of act or actuality as that which really exists here and now—a physical object. Another way to think of act is that which is ‘informed matter’. (In classical philosophy, matteris not form and form is not matter. Form is the essence of a thing or that which makes something the kind of thing it is and without which it can not be. Ordinarily, essence is considered distinct from existence. This is one reason why all reality has an immaterial as well as material elements.) ‘Potential’ or ‘potency’ is simply all the capacities for change, transformation, or movement that which is in act has. For example, a student has the capacity to become a great mathematician if she uses her rational capacities well. A rubber ball has the capacity or ability to be melted down and formed into a figurine, balloon, or tire. Potential is another way of describing all the possible modes of being something has (it is always innate to that which is in act). Potency is never unlimited, however, and is governed by the essence, nature, or form a thing has—and this will be important when we get to Heisenberg’s understanding of probability and atomic potency. For example, a hamster will never become a helicopter pilot, and a cephalopod will never become an architect because potency only relates to the nature (or essence) of the thing itself. Act and potency are metaphysical co-principles that help us make sense of the world around us. The act/potency distinction is an absolute feature of reality and is accepted by all serious philosophers from the classical tradition through the early modern period, including neo-Platonists and Aristotelians. For example, the neo-Platonist philosopher, Plotinus, appropriated Aristotle’s categories of act and potency when describing change.
Part two will specifically focus on Werner Heisenberg’s book, Physics and Philosophy with some concluding remarks from Max Planck.
Works Cited:
Dirac, Paul. The Principles of Quantum Mechanics. Oxford, Clarendon Press, 1958.
Silva, Ignacio. “Werner Heisenberg and Thomas Aquinas on Natural Indeterminism.” New Blackfriars, 2013, 635 – 653.
Although
Aquinas applies the concepts of act and potency to almost every facet
of existence, from natural science to the features of the intellect,
and even to the characteristics of the soul and angels, the best
starting point to understand the important categories of act and
potency is the relationship these ideas have with Being. A large
part of Aquinas’s philosophical methodology is to distinguish and
apply the categories of act and potency to all of reality. (Sometimes
Aquinas uses the word “powers” to mean innate potencies or
abilities.) Aquinas himself tells us that all reality, or Being, can
be divided between act and potency. “Potency and act divide being
and every kind of being” (400). At another point Aquinas explains,
“Since Being properly signifies that something is, in act, and act
is properly ordered to potentiality, a thing is, in consequence,
called Being absolutely according as it is primarily distinguished
from that which is only in potency; and this is each thing’s
substantial Being” (23). Furthermore, Aquinas expands upon the
nature of Being, “Being is the actuality of every form or nature;
for goodness or humanity are spoken of as actual only because they
are spoken of as being. Therefore, being must be compared to
essence, if the latter is distinct from the former, as act to
potency” (17). Something is “in act” or in the state of
actuality when it is existing in physical reality or knowable through
the intellect. Echoing Aristotle, Aquinas tells us “everything is
knowable only in so far as it is in act” (24). The concept of
Being which is the most general concept we have of reality, can
nevertheless be delineated between act and potency.
Being,
however, has two senses — one sense refers to physical objects of
reality and, in the second, intellectual objects of the mind such as
statements, ideas or concepts such as goodness or humanity, and
mathematics. Again Aquinas explains, “’To be’ can mean either of
two things. It may mean the act of being, or it may mean the
composition of a proposition effected by the mind in joining a
predicate to a subject”
(17).
In sum, all of reality exists in one way or another in act —
either in acts of perception or acts of the intellect. It is
important to keep in mind, also, that Aquinas does not hold to a
separate realm of ideas as Plato does, or the idea that the mind
itself determines reality. As will be explained later, Aquinas holds
that form and matter are always united together. In his
epistemology, however, Aquinas holds that the natural physical things
of this world (things existing “in act”) have their own
intractable reality and they are known by way of the five senses. It
is through abstraction that one realizes essences and universals that
exist in the intellect. For example, “redness” is realized by
viewing several red objects. Aquinas, following Aristotle, is
grounded in nature and believes that the physical objects of this
world have their own inherent and intrinsic characteristics and that
these characteristics can be known through abstraction. In
other words, reality is the determinate of order.
According to Aquinas, “Our intellect cannot know the singular in
material things directly and primarily. The reason of this is that
the principle of singularity in material things is individual matter,
while our intellect… understands by abstracting the intelligible
species from such matter. Now what is abstracted from universal
matter is the universal” (461). Aquinas indicates that it is
possible for the intellect to know the particular through reflecting
on the universal. All Being, nonetheless, exists in the universals
and particulars that make up the being and becoming of this world.
For
Aquinas, Being includes act and potency, but how does change actually
take place in the realm of becoming? More specifically, what is the
cause of change? With the exception of universals, virtually all
things of the physical world are subject to change or movement. As
noted earlier, both living and non-living things experience change.
Change is the actualization of a thing’s potential. Aquinas
provides this definition of change, “A thing requires to be moved
by something in so far as it is in potency to several things; for
that which is in potency must be reduced to act by something actual,
and to do this is to move” (658). Change, then, is potency reduced
to act. However, an outside and additional element is necessary to
bring about change. Potency is needed for change, but it is only a
necessary condition, not a sufficient condition to bring about
change. Aquinas explains, “Now it is impossible for a thing’s
being to be caused by its essential principles, for nothing can be
the sufficient cause of its own being, if its being is caused”
(17). In other words, for an acorn to change into a beautiful oak
tree, more than potential is needed. In order for an oak tree to
develop from an acorn, the acorn must be nurtured by sunshine, rain,
nutrients in the soil, and time. Something else, always itself in
“act,” is needed to actualize a potential. “For whatever is in
potency can be reduced to act only by some being in act” (14).
Potency itself cannot bring about act — just as non-being cannot
bring about being.
That
which reduces a potential to act is called a cause and a quick
overview of Aristotle’s famous four causes is, therefore,
necessary. Aquinas is fully committed to the Aristotelian four
causes. The first cause is the material cause — that out of which
something is actualized. The second cause is the efficient cause —
that by which something is actualized. The third cause is the formal
cause — that into which something is actualized. The fourth cause
is the final cause — that for the sake of which something is
actualized. A biological example will help explain how these four
causes work in the physical world. To understand the basics of the
human heart, it is important to know what it is made of — its
material cause. In this case, the material cause of a heart is
muscle. The efficient cause rests in the DNA that structures and
orders cells in such a way as to create a muscular heart and not a
kidney or spleen. The formal cause is that which the heart muscle is
fashioned into — ventricles, arteries, aorta, etc. The final
cause serves the purpose of pumping blood. For both Aristotle and
Aquinas, final causes are significant and found whenever cause and
effect relationships are seen. The totality of the three previous
causes all serve a goal or ultimate end, culminating in the final
cause. Focusing on act and potency, the efficient cause is that
which actualizes a potency. That is why Aquinas says, “Now
everything which is in any way changed is in some way in potency”
(38). In other words, there is always an external component to a
change which reduces potency to act, and that external component is
the efficient cause. The builder of a ship is the efficient cause of
the ship, and the DNA in the acorn is the efficient cause of the oak
tree.
All
things in act, therefore, are the subject or cause of change. That
which is in act is always a composition of act and potency.
According to Aquinas, all things are made up of a composition.
“Thus, in everything which is moved, there is some kind of
composition” (39). One of the metaphysical aspects of reality is
that the normal everyday things of this world are composed of act and
potency. For Aquinas, another significant aspect of all of reality
is the composition of form and matter. Aquinas explains, “matter
is that which is in potency” (15). And this relates to change as
well, according to Aquinas, “For just as matter, as such, is in
potency, an agent, as such, is in act” (21). The twofold
composition of form and matter is simply a restatement of the
Aristotelian understanding of formal and material cause. It is also
important to understand that things which change according to a final
cause must also be composed of form and matter. Without form there
would not be an essence to something and an inherent or final nature
could not be realized. Aquinas explains how this final end is
related to act and form, “upon the form follows an inclination to
the end… for everything, in so far as it is in act, acts and tends
towards that which is in accordance with its form” (27). For
Aquinas then, the immaterial aspects of causation are always
connected to act and potency, and form and matter.
In
addition, that which is in act is combined with form and matter,
“being is the actuality of every form or nature” (17). Just as
everything is composed of act and potency, all things are composed of
form and matter. “Hence, being itself is the actuality of all
things, even of forms themselves” (21). As we have seen already,
being is that which is in act. We can therefore understand, that
which is in act is also combined of form and matter. Aquinas
explains that universals and essences can be infinite, but form is
bound and contracted to matter, “Just as immaterial things are in a
way infinite as compared to material things, since a form is, after a
fashion, contracted and bounded by matter, so that form which is
independent of matter is, in a way, infinite” (620). In other
words, apart from universals, essences, or abstractions, forms are
always in combination with matter and that which informs, or
participates in the transformation of matter when it changes, and
matter is that which participates in the potential of receiving the
form. “Forms which can be received in matter are individualized by
matter” (16). Echoing Aristotle, Aquinas holds that in physical
objects, forms are inherent or immanent in the things themselves.
As
it turns out, the concept of potency is powerful and helps to provide
a foundation for understanding the metaphysical structure of things
that undergo change in this world. Therefore, wider implications of
the act/potency distinction warrants exploration. From physical
nature to human beings, everything that is in act is also in potency.
Potency, therefore, precedes and supersedes actuality and provides
continuity when things change because that which is in act will
change according to its nature, or essence, through potency. Potency
is not something that can be measured by the tools of the physicist,
but its effects can be. Science, after all, is not interested in
matter in and of itself, but rather in the properties, capacities,
and possibilities that the matter contains by virtue of its potency.
Whenever a drug manufacturer gives a list of possible side effects
(such as bleeding, restlessness, bloating, blindness, etc.) it is
explaining the potentialities that might occur if certain conditions
are met. In information science, we know that computers only perform
as they do because electrons have certain properties and not others.
Finally, we do not yet know the capacity and limitations of the human
mind and intellect. The capacity for the mind to grow, develop, and
learn speaks to the potential of what it means to be human. Human
beings are amazing and have the ability to adapt, appropriate
knowledge, and develop greater and greater abstraction. Pure
potentiality can never be measured empirically, but to deny its
reality would be intuitively and conceptually absurd. Aquinas’
act/potency and his correlative form/matter distinctions make the
most sense out of reality and provide a significant foundation for
understanding the metaphysical structure
of change and the world we live in.
Works Cited
Aquinas,
Thomas. The
Summa Theologica, Volume 1.
Great Books of the Western World. Vol. 17. Encyclopedia Britannica,
Inc., 1999
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