Thomas Aquinas

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 … 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.