An Introduction to the Five Ways of St. Thomas Aquinas, Part 4

In the last article, I presented St. Thomas Aquinas’ reply to the argument from evil atheists present against the existence of God. Here, I’ll present Thomas’ reply to the second objection: that everything in the created order can be explained by natural or human causes, so there’s no need to posit the existence of God.

Reply to the Second Objection:

Thomas answers by pointing out that there’s at least one thing in nature that can’t be explained by natural or human causes: all things in nature that act toward a final end do so regularly, that is, “always or almost always.” It’s this regularity that must be explained, not the randomness that we also find in nature. Thomas explains that this regularity, this purposeful acting toward final ends, must be “directed by a higher agent,” One Who is not directed by any other. Otherwise, if everything could, indeed, be explained by natural causes, we would have no regularity at all, only random, haphazard ends, as we might see in the pattern of sand dunes created by the wind, or the pattern of rocks at the foot of a mountain after an avalanche. That’s not what we observe in the natural order, however, and the regularity we do observe must be explained somehow.

Thomas shows that the existence of God isn’t just the best explanation for the regularity we observe in nature, but the only explanation. Why? Couldn’t the process of evolution, of natural selection, explain the regularity we see in living things? Just the opposite. The process of natural selection presumes the regularity in nature. Consider that long-necked giraffes survived while short-necked giraffes died out, because the long-necked giraffes could reach the vegetation at the top of the trees that the short-necked giraffes couldn’t. But, their survival depends on the regularity of long-necked giraffes mating and producing other long-necked giraffes, and not short-necked giraffes. If the result of mating was random-necked giraffes, there could be no such thing as natural selection. So it is with all living organisms. As well, natural selection can’t explain the regularity in non-living objects, such as the boiling point of water, the creation of water molecules from two hydrogen and one oxygen atoms, and the orbits of the planets and other celestial bodies.

Can the laws of physics and nature explain such things? They can certainly tell us what to expect from nature because of the regularity we find there. Rocks don’t fall up, and kangaroos don’t have elephants for offspring. But, the laws of physics and nature describe reality. They don’t create reality. Natural and human causes utterly fail in explaining the ultimate origins of all that exists, never mind why there is something rather than nothing. These are philosophical questions. In answering these questions, philosophy turns necessarily to God as the final end of all.

One God or Five?

Do the Five Ways point to one God, or is it possible that they point to five different gods? For Thomas, it’s impossible that there’s more than one God, and his Five Ways demonstrate this. For there to be more than one God, all the “gods” would have to share the same essence while having their own distinct existence. But, God is that Being Who’s essence is existence. For God, essence and existence are identical. It’s not possible for two beings whose essence is existence to share an essence but not share an existence. Likewise, it’s not possible for essence and existence to be identical in two different beings. Two beings can’t share the same essential identity in every way, for to do so would mean that there was no distinction between the two. If there’s no essential distinction between two beings, nothing to differentiate one from the other, then that’s the same as saying that they’re the same being, and only one.

As such, if there were more than one God, there would necessarily be some distinction between the two. This distinction, though, could only be the result of some perfection or privation that one possessed and the other didn’t. But, God possesses all perfections and no privations, so the other being would simply fail to match up.

Finally, the order that exists in creation reveals a unity that can only be understood if there is unity in the cause of creation. There is one God.

Be Christ for all. Bring Christ to all. See Christ in all.