Aquinas's Fifth Way

[Angrboda]

A quick summary of Aquinas’s Fifth Way:

“…things that lack knowledge, such as natural bodies, act for an end, and this is evident from their acting, or nearly always, in the same way…watever lacks knowledge cannot move towards and end, unless it be directed by some being endowed with knowledge and intelligence…therefore some intelligent being exists by whom all natural things are ordered to their end.”
. . . .
2: The regularity of efficient causation requires that causes be determined to particular effects; such that, when, in the absence of a countervailing influence, cause C is directed to effect E, then C tends to have E as a result.

I think to answer Aquinas more directly, I would note that all interactions are governed by four fundamental forces - gravity, electromagnetism, and the strong and weak nuclear forces. These four forces are sufficiently simple in their operation that they require no intelligence to explain their effects. If the forces weren't so atomistic and one-dimensional, an argument might be made that an intelligence is required to explain their regularity. At higher levels, such as in the behavior of plants and animals, or say the behavior of the tides, without this lower reduction to the four forces, the behavior of these higher order systems begs some explanation. With a reduction to these four forces, parsimony kicks in and no appeal to intelligence is required. One might still appeal to behaviors which don't seem reducible to the four forces, such as consciousness or free will, but then it becomes obvious that this becomes an argument from ignorance, a god of the gaps argument. "I can't explain why cause and effect are so regular, so they aren't.... therefore a regulating intelligence is required."