Turning to more abstract and universal matters, the philosopher Parmenides of Elea (in southern Italy) tackled the perplexing issue of permanence versus change in the world. He convinced himself that everything in the universe must be eternal and unchangeable. Change requires motion, he reasoned, and motion requires empty space. But empty space equals nonexistence, which by definition does not exist.
According to the passage, Parmenides' theory that things do not move or change is grounded upon his assumption that:
Correct
Incorrect
The correct answer is (D).
Getting to the Answer: "According to the passage" means that the answer will be stated by the author, so locate the place in the passage where the author talks about Parmenides' theory. The reasoning behind the theory is "Change requires motion ... and motion requires empty space. But empty space equals nonexistence, which by definition does not exist." A summary of this theory might be that Parmenides assumes that nothing moves or changes because empty space does not exist for it to move into, so find the answer that matches this summary.
(A) Incorrect: rational thoughts do not play into Parmenides' theory of motion
(B) Incorrect: this answer distorts Parmenides' conclusion that motion requires empty space