Case Study:  HOW COSMOLOGY BECAME A SCIENCE  

The Book of the Cosmos. Imagining the Universe from Heraclitus to Hawking. 

Ch. 6. The Potency of Place, Aristotle. “Aristotle’s writings on physics and the heavens establish concepts that undergirded much of humankind’s understanding of the world for almost two millennia.”

First passage:

• What is “the potency of place”? Is this a natural concept? How does it differ from our current views about space?
• What does it mean, that “fire, earth and the like” are “elementary natural bodies?”
• Contrast the concepts or relative and absolute position.
• Why does Aristotle quote Hesiod?
• Consider the concept of place presented by Aristotle. Is this something directly accessible by the senses (i.e. sensible)?

Second passage:

• What concept does Aristotle take as more fundamental, space or time? 
• How does one measure space? Time? Movement?

Third passage:

• Aristotle gives three meanings to the word “heaven.” How are these related to present-day usage of this term?
• Does Aristotle consider the possibility of things existing in the universe, which are not sensible?

Fourth passage:

• As regards the position of the earth, what are the “facts of observation?”
• Why did the Pythagoreans believe fire to be at the center of the universe?
• Where is the “center of the animal?”
•  What kinds of arguments does Aristotle use to rebuke others’ arguments about the shape and size of the earth?

Fifth passage:

• How is it different, for the earth to be the center of the universe, or for the earth to be placed at the center of the universe?
• Aristotle explains why objects move toward the center of the earth, why the earth itself does not move, and why the earth is spherical. What parts of his argument are based on observation, and what parts reflect his personal philosophical bias?

Sixth passage:

• Aristotle concludes that the earth “is not of great size.”  Are his arguments all equally valid? How did he get the information that he uses to support his conclusion?
• Put yourself in the position of a common person in Aristotle’s time, how would you react to this statement?

The article as a whole:

• Aristotle’s approach to cosmology is very different to that of the stories of traditional cultures. How?
• Aristotle seems to support all his statements with rational arguments based on observation and logic. Is this really the case? 
• Are all of Aristotle’s observations actually things he saw himself, or had first-hand reports about?
• What are the fundamental philosophical assumptions, about the natural world, that Aristotle relies upon implicitly?