The Will to Act and the Paradigm Shift Away From Aristotle’s Physics


ABSTRACT: The present study seeks to put together a critical assessment of the role that that “Will,” actualized through techné, played in Aristotle’s physics. It will be shown how said concept of Will led to a theoretical fissure of the Aristotelian cosmos between the natural and the artificial, which was finally detrimental to the sustainability of his scientific proposals. Furthermore, light will be shed on the incompatibility between Aristotelian physics and mathematics, an area of knowledge that was to become the primordial tool of modern scientific inquiry. As a manner of conclusion, brief remarks will be made on the progress—if any—of science across history in light of Karl Popper’s views on the subject.

In The Structure of Scientific Revolutions (1962), Thomas Kuhn argued that the dynamic evolution of science is not explained by the linear accumulation of new knowledge. On the contrary, science undergoes periods of theoretical revision that often destroy, not build upon, previous paradigms. Aristotle, whose ideas regarding physics dominated most of the history of western thought, formulated a framework of the cosmos where a rational account of Will brought about the principle that governs the world around us. The present study has been broken into two sections. The first section seeks to shed some light on the role that “Will,” actualized through craftsmanship, played in Aristotle’s physics. Secondly, some of the reasons that finally lead to a scientific paradigm shift away from Aristotle’s theories during the Age of Enlightenment will be examined.


It is difficult, from a modern perspective, to understand exactly what the study of physics meant for the ancient Greeks. When we talk about physics, we often refer to the study of matter, its properties, and its motion. Physics, in the modern sense, governs over everything that we can perceive through our senses (light, sounds, objects of any sort, etc). Yet, this is not what Aristotle had in mind. The word physics etymologically stems from the Greek word physus, which is often translated to English as “nature.” However, “nature,” a relatively ambiguous word in the first place, did not have the same meaning for the Ancient Greeks. When discussing nature[1], or physus, they were referring to something that had to do with change and growth. We could say, to use the word in the Aristotelian sense, that the “nature” of an acorn is to become a tree or that the “nature” of an egg is to become a chicken. Nature, for the ancient Greeks, entails a principle of motion that is dictated internally by the object’s essence[2].

Objects such as animals, plants, the earth, water, air and fire, belong to the Aristotelian class of natural entities (192b8). He claimed that such subjects have an independent and spontaneous Will to change into various forms. Static entities, such as a stone or the sand in a dessert, were not strictly speaking the main constituents of Aristotle’s natural world. Stones can move only insofar as the river’s current carries them along or insofar as a human grabs them and throws them in the air, for instance. Likewise, the dunes of the dessert move, not due to an internal principle of motion that guides their behavior, but only to the extent the wind blows them across the plains. However, stones and sand do belong to the natural world in the sense that they are constituents of an entity that has an internal principle of motion —earth, in this case (193a15). In Aristotle’s words, nature is “a type of principle and cause of motion and stability within those things to which it primarily belongs in their own right and not coincidentally” (Aristotle 192b22). Unlike the wind, animals, or water, stones and sand do not have a spontaneous Will to act.

Objects that are a product of human craftsmanship (of techné), such as a house or a bed, are certainly not part of nature (Aristotle 192b15). According to Aristotle, these kinds of things come to be not due to an internal principle that dictates what it is for them to become, but they are only insofar as a human being manipulates them or crafts them according to their various uses —their being is contingent upon the Will of humans. According to Aristotle, we, individuals endowed with the ability to make choices and capable of initiating motion, are able to shape wood into a bed in order to fulfill a functional purpose —in this case, resting more comfortably on an elevated surface. Likewise, we are able to literally “give form” to a lump of bronze that lacks a crafted shape. This takes us to the four causes that are necessary in order to explain the change of an entity that does not inherently contain the principle of spontaneous movement. The four causes are: (1) the material cause, which explains the physical component of the entity; (2) the formal cause, which explains the form or shape to which a thing corresponds; (3) the efficient cause, which is what we generally mean by “cause,” the original source of the energy that allows for the change; and (4) a final cause, which is the purpose it fulfills. For instance, bronze (the material cause) is shaped (the efficient cause) in order to constitute a statue (the formal cause) by the artist, who designates the purpose of its existence (the final cause). Thus, in Aristotle’s view of the cosmos there is not only matter and form, but also purpose. He says, for instance, that the existence of bricks is not coincidental; they have the purpose of becoming the material cause of a house (Physics, 200a25).

Aristotle, I believe, uses the previous principle of change in artificial objects in order to develop an analogy that may apply to natural objects as well, with certain adjustments. The logic, though very similar, has two basic differences. Let us proceed to construct the analogy in gradual steps: In regards to the material cause, just like the statue is made out of bronze, a musician is made out of flesh and bones. In terms of the formal cause, just like bronze constitutes the statue, flesh and bones constitute the form of the human being who is trained in the art of music. Yet, with regards to the efficient cause, the reasoning is somewhat different for natural and artificial objects. We discussed previously how natural objects have an internal principle of motion which artificial entities lack. In that sense, while the craftsmanship of the artist is a necessary condition for a statue to come to be, a man can become a musician by virtue of his own Will. Consequently, while bronze is potentially a statue contingent to the existence of an artist that makes the process come to be, a human is potentially a musician by virtue of his own ability to chose to become one. In that sense, the change that governs upon artifacts is contingent upon the Will of an external mover, contingent upon techné. Ultimately, with regards to the final cause, there is also a significant distinction between natural and artificial objects. In artificial objects, as discussed, an unmoved mover provides the final cause. For instance, the artist designs the end of the statue, and he will initiate motion in order to actualize what is potentially a statue (256a11). In natural objects, on the other hand, a first unmoved-mover gives the purpose. “We find, then, that among things that come to be and are by nature, things that are for something,” says Aristotle (199a8). This has to be the case since we would have an infinite regress otherwise, had we not had a first unmoved mover to designate the purpose of existence of the natural objects. An infinite regress, for Aristotle, is unfeasible. It is necessary for anything that moves, to be moved by the activity of some mover. This may be due to the intervention of an unmoved mover, like for artificial entities, or due to the involvement of a first mover that is not moved by anything else[3] (256a15). Since motion must be “everlasting and must never fail,” Aristotle posits the existence of an eternal, ever powerful first mover (258b10). Aristotle’s teleological world eventually leads to the thesis of a creator, a designer, a first mover. In The Metaphysics, Aristotle says, “there is something that initiates motion without being moved, something that is everlasting and a substance and actuality” (1072a25).

It must be the case—thought Aristotle— that what is true of the relationship between the artist and the statue, is true about the natural world and the first unmoved mover. Just like we shape the bronze and give a meaning, a telos, for the statue to be, the first unmoved mover gives us —natural entities— the essence, end, and meaning of existence[4].

Aristotle’s world, hence, is one governed by Will. That is one of the reasons he rejects the existence of randomness; everything has a reason to be, be it due to the Will of a natural entity —through techné— or else the Will of the first unmoved mover. It is true, however, that he does say that animals, entities of nature, do not have the capacity of Will. The fact that spiders build webs is not due to personal Will or deliberation but due to instinct—claimed Aristotle. This is evidence of the teleological design present in nature, he concluded. Since a spider’s web or a bird’s nest cannot come to be out of sheer randomness, and since birds and spiders do not have the capacity of Will or, as a result, techné, then they must be a direct creation of an external entity. In other words, it would seem to follow, animals and plants are entirely bound to the Will of the first unmoved mover.


Aristotle’s physics were the scientific paradigm until Galileo. However, Galileo’s observations of Venus’ phases, which were incompatible with the Ptolemaic model of the cosmos, over which Aristotle had a great deal of influence, set the evolution of science on a completely different path. It would be futile to enumerate particular flaws in Aristotle’s Physics in light of what is accepted today in modern science. Indeed, it is unlikely that “heavy things naturally move downward and light things upward,” as Aristotle claimed (200a3). A modern scientist would explain that the earth’s gravity causes all matter to move towards the earth’s core —what Aristotle called downward?— but denser fluids put pressure on lighter fluids in a way such that the latter seem to go upwards, away from the earth’s center of mass. However, Aristotle’s “mistaken”[5] argument regarding gravity seems like one that someone with the information and technology available to him at his time could reasonably make.

Therefore, it is more important to focus in broader aspects that —I believe— finally led to the paradigm shift away from Aristotle’s theory. At the most basic level, Aristotle made a big assumption when he divided the cosmos between natural and non-natural entities. In contrast, I do not see, based on what I can perceive, anything in reality that does not belong to the realm of nature. In other words, because humans shape their surroundings in different ways, the surroundings themselves do not cease to be natural. There is no fundamental distinction between the relation of a spider to its web or the relation of a human being to his or her house. In that sense, we either have no free Will, assuming that is the intrinsic nature of animals, or both animals and we have the capacity to develop techné, where free Will is a necessary condition.
Aristotle might argue in return that a house or a bed are not natural since they do not have the capacity to be self-sustaining. Aristotle argues, “a man comes to be from a man, but not a bed from a bed. In fact that is why some say that the nature of the bed is not the shape but the wood, because if it were to sprout the result would be wood, not a bed” (192a10). In that sense, a bed requires an “artificial” action by a human, a bed-maker, in order to exist. That is, Aristotle claimed, a proof that there is a distinction between the products of nature and the products of human beings (which can create objects that are outside of nature, or in other words artificial). However, just as a bed, a mule (the offspring between a female horse and a male donkey) does not have the capacity to be self-sustaining either. Mules are sterile; a mule does not come to be from a mule! Yet, it is very clear, even for Aristotle, that a mule is a natural creature[6]. Therefore, it is not the case that a natural object must be self-sustaining—mules are not, after all. Consequently, reductio ad absurdum, there is no reason to suppose that a bed is not a natural object. Similarly, a volcano, what Aristotle would define as a process of “nature,” is the consequence of tectonic pressure underneath the earth’s crust. A volcano does not come to be from a volcano. Yet, again, a volcano is clearly a natural process. Furthermore, we can create machines that can put together other machines like themselves. As a result, theoretically, machines (which would not be part of Aristotle’s natural world) can come to be from machines.

Beds, as Aristotle rightly argued, do not come to be from beds. Indeed, a human being is a necessary condition to bring about their existence. However, a human being by itself is not a sufficient condition to bring about the existence of another human being. The growth of a fetus requires nutrients external to the mother, oxygen, a certain temperature, etcetera. Thus, it is not the case that we —according to Aristotle, natural beings— move and shape a static and independent world spontaneously. We are both shapers and shaped by our surroundings[7].

Why was this distinction between the natural and the non-natural so misleading for Aristotle’s theories? He saw that human beings, through craftsmanship and Will, could bring about changes in order to create artificial objects that, he thought, were not part of nature. An artist, through his talent and Will to act, could actualize a lump of bronze or marble that could potentially become a statue. By use of the analogy previously described, I think Aristotle thought that a similar method applied to natural processes. The first unmoved mover is to natural agents what natural agents are to artificial objects. In other words, God is to humans what Michelangelo is to the David. He thought that the end of our existence and our essence had to be defined by a macro first unmoved mover —a supernatural Will. Darwin was a fundamental figure in challenging the views of those that, like Aristotle, saw the human being as a special and elevated entity.

The work of the ancient atomists, Leucippus and Democritus, would resemble more what science was to become after the scientific revolution that Copernicus started in 1543 with the publication of De Revolutionibus Orbium Coelestium. The atomists believed that there was no meaningful end or purpose in nature. All there is is atoms colliding against each other in the void. Atoms, they believed, are indestructible; the have always been and will always be. Since all there is is matter, and matter can be calculated mathematically, everything that will happen, like mathematical proofs, has to happen necessarily—a deterministic view, in other words. Aristotle, on the other hand, rejected the explanatory powers of mathematics (194a), an instrument that would become the nucleus of the scientific world after Galileo. The Atomists asked not “What purpose did this event serve?” like Aristotle, but “What earlier circumstances caused this event to be?” (Russell 67). From a pragmatic point of view, it seems to be the case that the latter question, the one the Atomists dealt with, has given us more answers regarding the reality that surrounds us. In other words, as Thomas Kuhn would say, modern physics increased the power to predict natural phenomena by embracing a non-teleological view. The former question, Aristotle’s question, led science in the road of superstition and theology for centuries.

After Newton, adopting related principles to those outlined by the Atomists, it seemed like scientific knowledge had finally reached solid foundations and the future of the discipline would only build up[8]. However, just like with Aristotle, we were mistaken. Albert Einstein revised most of the principles that were thought to be rock-solid. Consequently, Karl Popper proposed a theory of the development of science that cannot achieve ultimate certainty about anything. The material world, he claimed, exists independently from the human mind. Given the fact that their ontological nature is separate, the physical world is ultimately impenetrable and incommensurable to the human intellect. Therefore, like in other fields, problems start to arise when individuals and institutions become fanatical on their views of “certainty.” However, how is Popper so certain? I am troubled with whether or not Popper’s theory can be turned against itself. Could it be that his theory could be revised opening the possibility to find scientific certainty? After all, Popper is arguing that we can never be certain about knowledge, and I suppose that also applies to his own theory. So, will science ever reach certainty? I think it is impossible to know[9]. But again, how could I be even certain about that?

Works Cited

Aristotle. Introductory Readings. Indianapolis: Hackett Company, 1996. Print. (refer to this source for both Physics and Metaphysics)

Bertrand, Russell. A History of Western Philosophy. New York: Touchstone, 1967. Print.

Kuhn, Thomas. The Structure of Scientific Revolutions. Vol. 3. University Of Chicago, 1996. Print.

Popper, Karl. Open Society and its Enemies. Abingdon: Frank Cass, 1973. Print.


  1. Thereof, the word “nature” will be used in accordance to the Ancient Greek connotation unless stated otherwise.
  2. The essence of X is the answer to the question: What is F?
  3. It is interesting how it seems impossible for Aristotle to have an effect without a proper cause in nature, but when he talks about the first mover having this particular quality the paradox instantaneously dissolves.
  4. Such explanation is parodied in Voltaire’s Candide.
  5. According to Karl Popper science can only work in the negative sense. That is, a scientist may only, with certainty, reject a theory as non-scientific but cannot, with certainty, put forward a theory as scientific.
  6. After all, mules seem to have the “internal” principle of motion that Aristotle emphasized so much.
  7. It would me interesting to wonder whether, in some ways, a bed can be a first cause. Imagine that your new bed is very uncomfortable. After a week of sleeping on it, you realize that you have developed problems in your back and you have to go to the doctor. Could it be said that the bed is the unmoved cause of these back problems? Aristotle would say no immediately (only natural objects are first causes). However, I think the answer to this question is not so clear.
  8. In the Open Society and Its Enemies, Popper heavily criticized Plato, Marx, and Hegel (tracing the theories of the latter two to Aristotle) for formulating teleological theories of history and science that unfold in accordance with universal laws.
  9. If we are aware that our theories have holes that remain unexplained, it seems clear that we have not reached ultimate certainty. On the other hand, even if it seems we have reached a “perfect” theory, we do not know what the future will bring and there is always the possibility that in the future a brilliant scientist will make us realize how wrong we were about what we though was certain (after all we ended up revising Newton’s physics).

Juan M. Botero-Duque (’10) is a Philosophy and Economics major at American University.

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