5 Fourth Way
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, 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 of heat, is the
cause of all hot things. Therefore there must be also something which is to all beings
the cause of their being, goodness, and every other perfection; and this we call God.
The Fourth Way argues for the existence of God because of the different levels of perfection. Aquinas states that in the first part of this proof that in beings “there are some more or less good, true, and noble.” He assumes that since there are beings with “more” or “less” of these qualities, there must be a being that has the “maximum” of these qualities. In the second part of the proof Aquinas seems to be connecting truth with being. He asserts, “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.” In the first part of this quote, Aquinas argues that the qualities of the good, true, and noble exist in a supreme being who has the maximum amount of these qualities. In other words, there must be a perfect standard in which people evaluate the “more” or better.The second part of the quote is puzzling: “For those things that are greatest in truth are greatest in being.” What does this mean? Kreeft states, “But a thing must first be before it can be good (thus whatever has goodness must also have being), and every thing that has being also has some goodness (cf. S.T. I, 5, 3); therefore goodness and being are coextensive. The concept of degrees of being can be understood if we remember that ‘being’ means not simply existence (‘to be or not to be’) but also essence (what a thing is, its nature), and this latter aspect of being admits of degrees.” Kreeft seems to be saying that there is a close relationship between being and goodness. To have being is to have some goodness. In other writings, Aquinas states to have being is good or goodness. Davies supports this point. He asserts, “To understand the Fourth Way one needs to realize that Aquinas regularly takes being, truth, and goodness to be related in a serious way. For him, something that has being is always to some extent good.” So Davies supports the idea that there is a relationship between being and goodness, but what about truth and being. Aquinas states that what is greatest in truth is greatest in being. Davies suggests, “He also thinks that things that exist and are, therefore, good in some way can be thought of as true in that they possess what our minds can latch onto as intelligible.” There is, therefore, a strong relationship between being and truth. Aquinas is saying that when we grasp truth that we are grasping what is real.
In the last part of the proof Aquinas states that what is greatest in being causes that being in others.
One might say that to be good, true, or noble, one must first exist. Kreeft thinks that the basic point in the fourth way is that “better implies best.” However, is it really necessary to assume a best because something is better? Maybe, we are comparing different degrees of being we see in others.