Taking a view exactly the opposite of Heracli- tus’s, Parmenides (born ca. 515 B.C.) believed that all change was an illusion. There is only one reality; it is finite, uniform, motionless, and fixed and can be understood only through reason. Thus, for Par- menides, knowledge is attained only through ratio- nal thought because sensory experience provides only illusion. Parmenides supported his position with logic. For example, like the earliest humans, he believed that being able to speak or think of some- thing implied its existence (reification) because we cannot think of something that does not exist.
Zeno of Elea (ca. 495–430 B.C.), a disciple of Par- menides, used logical demonstrations to show that change was an illusion. Imagine an archer firing at a target. He said that for an arrow to go from the bow (point A) to the target (point B), it must first go half the distance between A and B. Then it must go half the remaining distance, then half of that distance, and so on, never reaching the target since some halfable distance always remains. Therefore, it is logically impossible for the arrow ever to reach the target. The fact that it seems to do so is a weak- ness of the senses. This reasoning, usually known as Zeno’s paradox, can be expressed in many different parables.