“We can easily see that it is impossible for everything to be present in everything.”

The occasional use of terms such as “easily” (18) hints at Aristotle’s own confidence in his reasoning. His thorough approach to logic—a key demand of his own intellectual approach to philosophy—is designed in such a way that he hopes to lead the audience through every step of his rationality. Aristotle is certain that his own conclusions seem obvious and easy.

“The reason why earlier thinkers went astray is that they failed to make this distinction.”

Aristotle discusses those who have tried to address the ideas that he explores in Physics. He is willing to give these earlier thinkers the benefit of the doubt: It is not that they were less intelligent or capable than Aristotle, he suggests, but that they misinterpreted a key distinction. Aristotle’s reasoning separates him from these earlier thinkers, as he has succeeded in making the distinction thus he will not fall into the same trap.

“Some things exist by nature, others are due to other causes.”

The opening line of Book 2 functions as a treatise on nature itself, but also alludes to the complexity of the ideas which will be discussed regarding Change, Motion, and the Structure of Nature. The short sentence is an overview of both the book which will follow and Physics as a whole. This is a statement of intent by Aristotle, as he sets out to clarify the complexity of the natural world.

“On the other hand, there are those who do think that chance is a cause, but one which is opaque to the human mind, because it is divine and too supernatural for us to understand.”

While there are aspects of Physics which concede to the unknowable and the supernatural, Aristotle is averse to anything which cannot be reasoned. His commitment to logic is total, so that he looks down on any arguments which concede to anything divine or supernatural. Even these ideas—such as The Unmoved Mover and Eternal Motion—must be reached through logic and reasoning. The implication from Aristotle is that anyone citing the supernatural as an excuse not to investigate further has failed on some level.

“So I had better begin by explaining why a thing’s nature is a cause in the sense that it is a purpose, and then go on to discuss necessity and its role in natural objects.”

Physics is a complex work because Aristotle does not take anything for granted. His philosophical framework demands that he reason out every idea that he introduces. Rather than rely on a set of commonly held assumptions or beliefs, Aristotle delves deeper and deeper into abstract ideas to ensure that his philosophy—much like his analogy of the house—is built on solid foundations.

“For instance, it is an actual man who creates a man out of that which is potentially a man.”

While Aristotle deals with many abstract and complicated ideas, his stated goal in Physics is to illustrate how these natural sciences differ from mathematics in being related to something more tangible and concrete. The reference to man creating man, for example, is a reference to procreation and generation, which helps Aristotle ground his discussion of potentiality in concrete examples.

“Plato, on the other hand, has two infinites, the great and the small.”

Throughout the book, Aristotle makes a number of references to Plato and his school of thought. Often, Aristotle uses the position of his former teacher as a way to delineate his own beliefs. Plato has two versions of the infinite, Aristotle notes, but Aristotle wants to present an understanding of the infinite which does not rely on this distinction. This speaks to his desire to iterate on Plato’s work.

“Infinity turns out to be the opposite of what people say it is.”

Aristotle makes frequent reference to the philosophy of others while discussing Infinity and Continuity in Aristotle’s Philosophy of Time. This functions as a useful rhetorical tool, as it allows Aristotle to outline the foundational understandings of a subject before offering his critique and then his own interpretation. The understanding of others, he admits, may be flawed, but these flawed understandings—even when they are the opposite of what he believes to be true—still have some use.

“A natural scientist must have the same kind of understanding of place as he does of infinity.”

In Physics, Aristotle sets out to create his definition of the natural sciences. He achieves this through his logic and reasoning, yet he also includes a secondary goal which is to establish the idea of natural scientists themselves. His interest in the idea of place helps build his discussion of Change, Motion, and the Structure of Nature.

“Other things, however, such as a person’s mind and the world, are coincidentally in place.”

At the beginning of Physics, Aristotle wrote of his desire to ground his subject matter in the tangible, differentiating it from the more abstract field of mathematics. Throughout the book, however, Aristotle encounters a tension between the tangible and the abstract which prompts him to ground his ideas in “a person’s mind and the world” (89). He feels the need to make such references so as to remind the audience of why this particular subject is not as abstract as others.

“So this lot have not even reached the threshold of the issue, whereas those who claim that there is such a thing as void do better.”

Aristotle’s academic tone occasionally slips, especially when he is referring to the work of philosophers with whom he disagrees. The reference to “this lot” (91), for example, is critical not only in the sense that he is saying that his peers have failed to fully comprehend an issue, but also in the informal way in which he groups them together.

“Now, there is such a thing as movement, and one kind of movement is circular movement.”

The notion of circular movement becomes important later in Physics. At this stage, however, Aristotle is already beginning to build up the idea in the minds of his audience. This use of foreshadowing as a rhetorical device speaks to the complex and assured way in which Aristotle approaches his argument.

“No, a change can only change coincidentally, as when there is a change from remembering to forgetting because the subject involved changes at one time to knowing and at another time to ignorance.”

Throughout the book, Aristotle poses questions to his audience. These are rhetorical questions, however, as Aristotle rarely asks a question to which he does not already know the answer. He answers his own rhetorical questions as though they were posed by other philosophers, an almost Socratic approach in which he is in dialogue with himself.

“But these problems lie outside our present enquiry.”

While Aristotle constructs a thorough argument for the field of natural sciences, there are occasional recognitions of the need to set the boundaries of discussion. Aristotle includes an idea, but notes that it lies beyond the “present enquiry” (129), hinting at both his intellectual curiosity and awareness of the sprawling, ambitious nature of his work.

“We should also decide which changes are opposite to which, and do the same for rest as well.”

Aristotle is a singular voice in the narrative structure of Physics, but his rhetoric also has an inclusive tone, employing the collective pronoun rather than the singular first person. “We should” (131) decide, he suggests, even though he is leading the discussion. In inviting his audience to consider “which changes are opposite to which,” he continues his investigation of Change, Motion, and the Structure of Nature.

“For example, if the magnitude ABC consists of the indivisible components A, B, and C, each of the parts of the movement DEB of an object X over ABC is indivisible.”

As the book develops, Aristotle includes an increasing number of formulae. Though he is keen to avoid abstraction and employs many analogies to shape his argument, the increased complexity of his subject matter means that these abstracted formulae become the most efficient way of explaining his point.

“We have already established the position on divisibility, and now we turn to explaining infinity.”

The casual manner in which Aristotle describes his imminent attempt to explain infinity speaks to the academic ambition of the work. Infinity and Continuity in Aristotle’s Philosophy of Time becomes increasingly prominent in this section, as infinity suggests a state that is somehow outside of time.

“Zeno’s reasoning is invalid.”

Aristotle does not respect the so-called paradoxes made famous by Zeno. He writes about them in an almost contemptuous fashion, taking them apart in a logical manner. In referencing earlier thinkers and attempting to debunk their views, Aristotle offers a new way of tackling the main issues in physics.

“The same analysis also applies to all the species of pushing together and pushing apart.”

Throughout Physics, Aristotle employs language borrowed from other fields of science to create an intellectual framework for natural science. He borrows the notion of species, for example, when discussing movement and change, in such a way that situates the subject in the same kind of intellectual organization as employed by naturalists when categorizing animals and plants.

“A good state is a completion, a bad state is a lack of completion, and so neither of them is an alteration.”

When Aristotle talks about the good or bad states in this fashion, he is not doing so in a moral sense. Rather, the scale of good or bad is applied to what degree something adheres to its complete nature. For a dog to be entirely a dog is good, Aristotle reasons, and anything that prevents it from being a dog is considered bad.

“That is why Zeno is wrong in arguing that the tiniest fragment of millet makes a sound.”

The degree of contempt which Aristotle appears to hold for Zeno is revealed not only in the thorough disproving of Zeno’s so-called paradoxes, but also in the way in which Aristotle returns to the unsoundness of Zeno’s arguments.

“Besides, how could there be such a thing as ‘earlier’ and ‘later’ if there is no such thing as time?”

Aristotle’s approach to Physics is to create a comprehensive demonstration of how logic and reasoning can be used to handle any philosophical problem. At the same time, however, Aristotle also recognizes the occasional need to appeal the audience’s lived experience of the real world. He does not need to explain in detail (though he attempts to do so) the nature of time with regards to earlier and later, because he believes that people have an innate understanding of how these function.

“Since change must always exist without failing, there must be a first agent of change (or perhaps more than one) which is eternal and unchanging.”

In the closing chapters of the book, Aristotle’s language and tone take on an almost religious sensibility which reflects the increasingly abstract nature of his subject matter as he addresses The Unmoved Mover and Eternal Motion. The use of terms such as “eternal and unchanging” (207) adheres to the language used in discussions of the infinite, but used in a broader, almost transcendental sense. As much as he wishes to keep the discussion grounded and tangible, Aristotle recognizes the need to deal in the abstract.