The Five Ways and God's Existence: The Fourth Way

This Fourth Way offered by Thomas Aquinas can often be confusing and hard to apprehend. Hopefully, in this short post, we will clear up the confusion with some clear explanations. First, I'll give a basic overview of this proof. Thomas argues for the existence of God based off the reality of the degrees of perfection we see in the world, as he puts it, the perfections of goodness, trueness, and nobility. We readily see and distinguish between various degrees of these realities. Now, Thomas says, it would be impossible to speak of better or worse degrees of perfection in beings unless there was a standard and source of perfection and being by which we measured and judged these beings and their perfections. This standard and source, Thomas declares, we know as God.

Some people might object to this proof, arguing that all judgements of good and bad are personal and subjective and therefore essentially devoid of any real meaning or significance. However, this objection fails because goodness is essentially tied in with ontological and inherent being and perfection, which are objective realities. Our perception of the realities of virtue, goodness, and being is not what creates or changes these things. Our thoughts about them are exterior to them and in no way cause them to vary in degree and measure. Therefore, our personal perceptions are irrelevant to the real existence of degrees of perfection in beings.

In conclusion to this short discussion, I'll present Aquinas's own words for you from his Summa Theologiae: "The fourth way is taken from the gradation to be found in things. Among beings there are some more and some less good, true, noble and the like. But 'more' and 'less' are predicated of different things, according as they resemble in their different ways something which is the maximum, as a thing is said to be hotter according as it more nearly resembles that which is hottest; so that there is something which is truest, something best, something noblest and, consequently, something which is uttermost being; for those things that are greatest in truth are greatest in being, as it is written in Metaph. ii. Now the maximum in any genus is the cause of all in that genus; as fire, which is the maximum heat, is the cause of all hot things. Therefore there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God."