jan 25, 1382 - Moving Earth
Description:
Nicole Oresme d.
The Parisian masters Jean Buridan and Nicole Oresme considered the possibility of the daily rotation of the earth.
1. This issue was apparently a topic of discussion even in the twelfth century; William of Conches remarks on a “crazed philosopher” who maintained it.
2. Buridan noted that we can observe only relative motion, so we cannot tell if it is we who are moving or the stars.
3. Buridan eventually rejected a rotating earth on the basis of the fact that an arrow shot straight upward falls back to its place of origin, rather than being left behind by an earth in motion.
4. Oresme argued that the arrow experiment does not prove anything, saying that the arrow also has impressed horizontal force, which would keep it moving along with the earth.
5. Oresme noted that a moving earth would be more economical, because the motion of one body in twenty-four hours would dispense with the necessity of the rest of the cosmos moving around the earth once a day.
6. In the end, however, Oresme rejected the possibility of diurnal motion. There is no way to decide between the two possibilities, so he goes with the commonsense answer.
B. It is important to note that Oresme’s motivation was to show that there are some cases in which the exercise of reason fails to give us an answer; therefore, reason should not be used to impugn articles of faith. (Of course, he’s used argument to argue for the insufficiency of argument!)
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