Aquinas' first way to prove the existence of God is the argument from motion. He argues that everything that is in motion is moved by something else, and that this chain of motion cannot go on indefinitely. Therefore, there must be a first mover, which is God.

Aquinas' second way to prove the existence of God is the argument from efficient cause. He argues that every effect has a cause, and that this chain of causes cannot go on indefinitely. Therefore, there must be a first cause, which is God.

Aquinas' third way to prove the existence of God is the argument from contingency. He argues that everything that exists could have not existed, and that therefore there must be a necessary being that is the cause of all other beings. This necessary being is God.

Aquinas' fourth way to prove the existence of God is the argument from degrees of perfection. He argues that there are degrees of perfection in the world, and that this implies the existence of a perfect being, which is God.

Aquinas' fifth way to prove the existence of God is the argument from the order of the universe. He argues that the universe is ordered and purposeful, and that this implies the existence of an intelligent designer, which is God.

The main objection to Aquinas' Five Ways to Prove the Existence of God is the problem of evil. If God is all-powerful, all-knowing, and all-good, then why does evil exist?

Aquinas responds to the problem of evil by saying that evil is a necessary part of the universe. He argues that evil is the privation of good, and that it is impossible for there to be good without the possibility of evil.

Aquinas' Five Ways to Prove the Existence of God are the proofs of the existence of God that are most widely accepted by philosophers. They are also the proofs that are most consistent with the teachings of the Catholic Church.

The problem with Aquinas' argument from motion is that it relies on the unproven assumption that there cannot be an infinite regress of causes. It is possible that there is an infinite regress of causes, in which case there would be no first mover, and therefore no God.

The problem with Aquinas' argument from efficient cause is that it ignores the possibility of self-causation. It is possible that something could cause itself to exist, in which case there would be no first cause, and therefore no God.

The problem with Aquinas' argument from contingency is that it ignores the possibility of necessary beings. It is possible that there are beings that could not have not existed, in which case there would be no necessary being, and therefore no God.

The problem with Aquinas' argument from degrees of perfection is that it ignores the possibility of multiple perfect beings. It is possible that there are multiple beings that are all perfect, in which case there would be no one perfect being, and therefore no God.

The problem with Aquinas' argument from the order of the universe is that it ignores the possibility of natural laws. It is possible that the universe is ordered and purposeful because of natural laws, rather than because of an intelligent designer.

The main criticism of Aquinas' Five Ways to Prove the Existence of God is that they are based on unproven assumptions. For example, the argument from motion relies on the unproven assumption that there cannot be an infinite regress of causes. The argument from efficient cause relies on the unproven assumption that everything that exists has a cause. The argument from contingency relies on the unproven assumption that there cannot be necessary beings. The argument from degrees of perfection relies on the unproven assumption that there cannot be multiple perfect beings. The argument from the order of the universe relies on the unproven assumption that the universe is ordered and purposeful because of an intelligent designer.