The Fifth Way

The Fifth Way of Thomas Aquinas likely appeals to many of you as obvious:

1. Whatever lacks intelligence and exhibits order and regularity is the result of design. (Premise)

2. The laws of nature lack intelligence and exhibit order and regularity. (Premise)

3. Therefore, the laws of nature are the result of design. (From 1 and and 2)

A circularity of causes and its irrelevance

Imagine a circle of causes.  Each part of the circle causes the next part, and so on, until the very first part is arrived at again.  Does this avoid the need for a First Cause?  Not at all, especially if one excepts even a modest version of the Principle of Sufficient Reason (PSR):

PSR: Everything that exists has an explanation of its existence, either in the necessity of its own nature or in an external cause.

The problem with a circularity of causes is that no explanation for the circle is given.  Why is there a circle, rather than no circle at all?  Unless one is willing to bite the bullet and say the circle exists by a necessity of its own nature, which is highly unlikely, if not impossible (necessity entails an essence identical with its existence), then on the PSR one is required to reject the possibility of a circularity of causes: the circle has an external cause.

The Fifth Way

This is the argument that moved me from agnosticism to theism.  

1. Whatever lacks intelligence and exhibits order and regularity is the result of design. (Premise)

2. The laws of nature exhibit order and regularity. (Premise)

3. Therefore, the laws of nature are the result of design. (From 1 and 2)

Since whatever transcends nature must also be timeless, changeless (since time is a measurement of change), immaterial, unique, and very powerful and intelligent, we have a sound argument for God's existence. Here's why:

Nature, or the universe, is the sum total of all physical space, time, matter, and energy. As a result, the Cosmic Designer must transcend time/change, and materiality. Moreover, the Cosmic Designer must be unique, or one. This is because whatever cannot change cannot exhibit any potentiality, and is therefore Pure Actuality. If there were more than one Pure Actuality, then there would be distinctions between them. Yet, to be distinct from actuality is to be non-actuality, in which case the latter cannot exist. The reason other things exist is because they are composites of actuality and potentiality.

Since there is only one God, it follows that all power and all intelligence is attributable to God. Hence, God is both omnipotent and omniscient. God is also perfectly good, since to only be partially good is to exhibit potentiality, which is impossible for God, who is Pure Actuality.