In Chapters Four through Fourteen of Book Two of Aristotle’s On the Heavens, the learned philosopher proposes to cut through the haze of persistent ambiguities and mysteries about the nature and function of the universe, declaring “it is well that we should seek to increase our understanding, though we have but little to go upon, and are placed at so great a distance from the facts in question.”[1]

This distance from facts, as Aristotle argues here and in other texts he wrote, should not discourage human beings from attempts to understand the world in which they live, however, as well as the entire universe that exists beyond known consciousness. Rather, such distance should only serve as motivation for human beings to bridge the chasm between the mere awareness of an idea and the profound understanding of it.

In these chapters of On the Heavens, Aristotle tells the reader that “there are certain principles” which can be known and applied in order to understand the universe.[2] More importantly, if the reader can apply these principles that are, in Aristotle’s mind, indisputable and “sufficiently explained,” he or she can understand people’s place within the scheme and order of the universe.[3] While much of On the Heavens is densely theoretical and seemingly focused primarily on the astronomical and the cosmological, the careful reader can discern some essential advice for living in a complex world, advice that is both timeless and universal.

In Book Two of On the Heavens, Aristotle goes to great lengths to explain to the reader in painstaking detail how the universe works. In fact, in chapters four through fourteen, Aristotle devotes most of his attention to developing his articulation of his elaborate cosmological theory: how the matter of the universe is shaped, how it occupies space and time, and how its constituent objects relate to one another. This theory is dense and complex, especially for a lay reader, involving arithmetic considerations of shapes and the ways in which they correspond to numbers, the geometry of circumferences and radii, and the dimensional notions of planes. He also offers a treatment of the elements—water, air, earth, and fire—and proposes an explanation regarding how each of these is comprised and what types of effects one exerts over the other. In this section of On the Heavens, Aristotle also begins to insert the human figure into this complicated equation, considering how perceptions affect the act and outcome of observation.

Much of this part of Aristotle’s philosophy on the heavens and the universe at large is delivered carefully and logically, each idea building sequentially upon the one that preceded it. The words Aristotle chooses to explain complex constructs are deliberately repetitive, seemingly for the purpose of emphasis, as in “the bodies below the sphere of the planets are contiguous with the sphere above them. The sphere then will be spherical throughout; for every body within it is contiguous and continuous with spheres.”[4] It can be all too easy for the reader to be overwhelmed by both the content and the style of this particular book of On the Heavens, which is characteristic of most of Aristotle’s philosophical writing, but the persistent reader will be rewarded with a handful of vital life lessons that remain relevant across all times and places, regardless of whether one understands the mechanics of the universe’s functioning.


The reader must be patient in order to discern these lessons. He or she must also be able to link the lessons together into a larger context, in much the same way that Aristotle has done in linking together the concepts that form his cosmology. This process need not be as complex as it might appear at first, however. Hidden within the dense lines heavy with redundancy, Aristotle has placed three lessons. The first explains how human beings face difficulties in achieving their goals because there are some matters that are simply beyond their control. The second lesson teaches that despite uncontrollable aspects of our beings, humans are the supreme species because of a hyper-developed cognitive capacity relative to other species. The third lesson, though, offers a thoughtful warning. With great capacities also come equivalent responsibilities, and we must always think about the means and the ends of our actions, and how each will affect other people. The universe depends upon striking a balance among all of the movers and all of their disparate movements.
The first lesson is delivered directly and in language that is fairly unadorned, considering Aristotle’s penchant for repetition and, at times, the unnecessary elaboration he offers that merely reasserts a point that has already been made. In Chapter 12, Aristotle says plainly to his reader: “To succeed often or in many things is difficult.”[5] At the most basic level, this lesson tells humans to understand and accept that failure is a part of a well-lived life; it is impossible, even when one exerts his or her best efforts, to succeed at every action or on every occasion. Aristotle links this teaching to two other lessons. Prior to delivering this pithy kernel of wisdom, he alludes to the fact that at least a portion of our actions are not—nor can they be—reflective of our own best efforts. Rather, they are a condition and outcome of luck and circumstance. To reinforce this point, Aristotle offers a metaphor that continues to resonate today. One man, he says, will have a healthy body without having to exercise it; another will require constant “hard training”[6] to achieve and maintain a healthy body, while a third man will work hard and never achieve the health he desires. Some things, Aristotle suggests, are left to the luck of the draw. The second lesson to which Aristotle links the teaching of the challenges of success is that which may be referred to as exponential difficulty. The more complex and demanding a task is, Aristotle explains, the more that will be required not only of the individual, but also of luck and circumstance, in order to fulfill the task and achieve a successful outcome. In his typical algebraic prose, Aristotle develops this idea in the following way: “In action, again, when A has to be done to get B, B to get C, and C to get D, one step or two present little difficulty, but as the series extends the difficulty grows.”[7]