Aristotle

As Aristotle viewed the world around him, he observed that things are moving and changing in certain ways. Aristotle discovered that certain things cause other things, which in turn cause something else. Aristotle believed that an infinite chain of causation was not possible, thus, a prime mover of some kind must exist as the first cause of everything that changes or moves.

The first evidence that Aristotle viewed was the world around him. He observed that everything is in motion, and that one motion causes another motion and so on. Much like billiard balls on a pool table. One ball hits another ball, that ball moves, hits a third ball, and the third ball moves. Like A causes B to move causes C to move etc. After careful observation, Aristotle noticed that everything is in motion, even the planets, and thus, there was a chain of causation. Aristotle believed that something can not come from nothing, that is, a thing can not pop in and out of existence, thus, there must either be an infinite chain of causation or a first cause/prime mover. Aristotle dismissed the possibility of infinite causation and instead attempted to prove that there is a prime mover or first cause. Aristotle also believed the universe was situated in a certain way. Aristotle believed that the heavens began just above the bottom of the moon and the everything above the lower portion of the moon was the heavens. In the heavens, Aristotle observed that everything was in a cyclical motion, and that the planets moved about each other in circles. If the planets moved about in circular motion then there must have been a cause to bring about their motion, thus, there must also be either an infinite chain of causation for heavenly bodies or a prime mover first cause of the heavenly bodies.

For Aristotle ‘local motion is the primary type of motion and the primary type of motion is circular motion' For Aristotle this means that everything is moving, and the best form of movement is movement in a circular motion because a circle is the perfect form of movement. It has no beginning and no end, its continuous and everlasting. Aristotle saw this motion in everything, even the human existence is that of a cycle. We are born, reproduce and die, in a continuous existence just as the heavenly bodies begin at one point and move around until they are at the beginning point again. Aristotle stated his point as the following:

"If, then, the same thing always exists in a cycle something must always remain actually operating in the same way, And if there is to be a coming to be and perishing, then there must be something else that actually operates in one way at one time and in another way at another time. The second mover, then must actually operate in one way because of itself, and in another way because of something else, and either because of some third mover or because of the first mover."

It is necessary, here, to explain what Aristotle called potentiality and actuality. Potentiality is the faculty something has, and actuality is the realization of that faculty. One has the ability to be musical, that is, one has the potential to be musical. If one decides to be musical then one has actualized their potentiality, that is, one has caused themselves to become musical. So then when Aristotle says ‘the second mover operates in one way because of itself,' it means the second mover has acted upon its potential and actualized it. For Aristotle things do not simply act on their potential because of nothing, there has to be a cause of the actualization, thus, when he said "...The second mover, then must actually operate in one way because of itself, and in another way because of something else." He meant that thing A has the potential to move by itself, but it does not simply move for absolutely no reason, thus, A moves because of its potential, and because of cause B. Aristotle said "It is all so evident...by saying that motion is in the thing moved. For it is actuality of the thing moved, brought about by the agency of the mover." The last part of Aristotle's statement, "and hence either because of some or because of the first mover. prime mover," Means that the cause of A moving is A's potential and B is either a third mover or is a first mover C.

The best way to summarize the statement made above by Aristotle is to use the example of billiard balls. Imagine there are 4 billiard balls labeled A, B, C, and D. Ball B has the potential to move but needs a reason to move. Ball C moves and caused ball B to move, thus, Ball B is caused to move by its potential and by ball C. Ball C also has the potential to move, but needs a reason. The reason ball C moved is because ball C has the potential to move, and was caused to actualize its potential by ball D, thus, ball