A Commentary on Aquinas's 5 Proofs

     Thomas Aquinas has 5 proofs in which he argues for the existence of a greater being, or God. My co-blogger Calvin intended to mention two of those proofs, but managed to mention three. The first proof he mentioned is what Aquinas calls the Proof of Efficient Causes. The second proof he mentions is the Proof of Design. The final proof Calvin mentions is the Proof of Graduation of Being. The other two proofs are similar in nature.
     One of those two proofs is the Proof of Motion. Essentially Aquinas argues that our senses allow us to perceive that some things are in motion, and that others are not. He then states that things come into motion when potential motion becomes actual motion. We now call this the transfer from potential energy to kinetic energy. He proceeds be declaring that things cannot be both potentially in motion, and actually in motion; it must be one or the other. If something is potentially, but not actually in motion, then it cannot be both potentially or actually in motion; this would change it to an object actually in motion. Because an object cannot be both potentially and actually in motion, an object not in motion cannot move itself. The sequence of motion cannot continue ad infinitum, so there must be a primary mover. This argument is very similar to the argument from Efficient Causes.
     The second argument is the argument from possibility and necessity. He states that things which come into and out of being are contingent beings, and that those beings exist in specific spaces of time. They could not always have existed. Therefore there could have been a time when nothing existed. A contingent being cannot bring itself into being; under the circumstance where all beings are contingent the universe would not have come into being. Therefore some being must be out of its own necessity. We call this being God.
     I personally prefer the Efficient Causes argument out of the 5; the other four seem less sound. A couple of them rely on assumptions and possible circumstances. For instance, the second proof discussed here requires that there be time when no contingent beings existed, without providing a basis for that assumption.
    All of the arguments are insightful, though, and certainly at least force non-believers to consider the existence of God.