On Water-Conducting Machines

This is the primary reason why the majority of the leading philosophers rejected the idea of a vacuum from the world. They consistently supported their position with compelling arguments.

However, some were found among them who believed that an infinite space, empty of any physical body, existed outside the world. They held this view for the following reason:

Any body placed in a specific location is necessarily surrounded and enclosed by another. For example, the earth is surrounded by water, and water is surrounded by air. Therefore, the entire body of the universe must also be surrounded and bounded in this way. Since no other physical body exists outside the world (which is the greatest, final thing that encompasses all others), it is necessary to establish an infinite, immaterial space outside of it. This prevents an endless progression of one body inside another. This space is nothing other than the often-mentioned void, or a place empty of any physical body.

CHAPTER IV.

Certain arguments of Aristotle against those who placed a vacuum outside the world, along with an attached refutation by Cleomedes.

Aristotle rises with very strong arguments and reasons against those mentioned above who claim a vacuum exists outside the world. He states that there is no place for a vacuum either within the world or outside of it. He argues that outside the world there is absolutely nothing, and therefore no vacuum. He reasons that a vacuum would necessarily have to be something, specifically a vessel or a container receptaculum: a container or space meant to receive something for some body. However, since no body exists outside the world, there can be no such container. To say that "nothing" is "something" is, in his view, completely absurd and inconsistent.

Furthermore, if this theory were accepted, the world would be carried away in an unregulated motion into infinity. It would have nothing to support or steady it. This does not even mention that its substance would be corrupted, diminished, and destroyed in such a state.

Moreover, if such an infinite vacuum were placed outside the world, it would follow that all other things are also infinite. This directly contradicts clear experience.

Regardless of how well Aristotle felt he had argued, Cleomedes attacks him quite harshly in the first book of his Meteors original: "Meteororum". Cleomedes claims that all of Aristotle's arguments are very easy to dismantle, especially for those who care for naked and immovable truth rather than the disguises of sophistry sophistry: clever but false reasoning used to deceive. He argues that an infinite vacuum outside the world must necessarily be defended.

Regarding the first point—that a vacuum outside the world would necessarily be a container for some body, and therefore that "nothing" would become "something"—Cleomedes thinks Aristotle’s reasoning is flawed. He argues that because there is no body there, it does not mean there is no vacuum. He considers Aristotle's statement just as absurd as if someone were to say that a water jar original: "hydria" cannot stand in a dry place that is empty of water.

To better explain his thinking, Cleomedes notes a distinction between types of vessels. Some, he says, are already full, such as the world or the universe. Others, however (to which the vacuum outside the world is compared), are simply capable of being filled by the introduction of some body. He argues that these latter types deserve the name "vessel" no less than the former.

To the second argument—the claim that the world would not remain in its place—Cleomedes replies: It is impossible for the world to move in a vacuum (meaning in an irregular and disorganized way). This is because the world maintains its firm rest at the center