In Aquinas’ arguments that reason logically toward the existence of God, he points out that as human beings we recognize that there are degrees of things. For example: shorter VS taller, fatter VS skinnier, darker VS lighter, colder VS hotter, etc. And along these lines we often rate things as good, better, and best.
What he points out is that in order for us to have the idea that one thing is better than another, we must have a standard by which all things are measured that can never be exceeded. That standard, he argues, is God.
We have to makes sure we understand his argument here: He’s not saying that we get the idea of goodness or hotness from the existence of God, but simply that the notion of “more and less” points to the necessity of a Being Who has put that concept into the reality of the universe. Since there is a “scale” so to speak, there must always be a top to the scale that can never be surpassed.\
Such a top to the scale requires an infinite being, hence it must be God.
Discussion is welcome!