In the first post in this series on Aquinas’s Fifth Way, I introduced and explored several historical examples of different “teleological arguments,” of which the Fifth Way is one. In this post, I will make some final distinctions between the Fifth Way and other teleological arguments, and then begin laying out, explaining, and defending Aquinas’s argument.
For the most part, the majority of teleological arguments make use of what we might call “extrinsic” teleology, whereas the Fifth Way is based upon intrinsic teleology; it is largely for this reason that I think the latter is much stronger and more successful than the former. To grasp this, we might consider an example: Suppose you’re walking along a beach and come across some sticks arranged into a word. The word, qua word, is teleological; it conveys meaning, “points to” some meaning beyond itself. The sticks, on the other hand, in themselves are not teleological, at least in relation to the word. A stick, in itself, does not signify anything beyond itself (what it is), unless such further signification is imposed upon it externally, as in the case when the sticks are arranged to depict a word. So, when you walk on the beach and come across the sticks arranged into a specific word which conveys a meaning, you most likely conclude that some rational agent, some intelligence, some human person, was causally responsible for arranging the sticks. Because sticks in themselves do not convey a meaning beyond themselves, and yet because they have been externally arranged to convey a meaning beyond themselves, you conclude that some intentional and purposeful agent has imposed the meaning.
This is a simplistic example of what many teleological arguments are essentially. Continue reading