We’re blogging through St. Thomas Aquinas’ Compendium Theologiae, sometimes called his Shorter Summa. Find the previous posts here.
This chapter is surprisingly topical given last year’s new English translation of the Roman Missal. In the Profession of Faith the phrase that had been translated “of one being with the Father” is now translated “consubstantial with the Father”. This is a difficult phrase, to be sure, but it has the advantage that at least it isn’t deceptively clear. Thomas has this to say about it:
It is vitally important to remember, when doing theology, that all of our speech about God is inadequate to the subject. We speak best when we speak negatively, about what God is not. When we say that God is infinite, we don’t mean that God is infinite in any mathematical sense; rather we mean that God is not finite, not bounded, not constrained. When we say that God is all powerful, we are simply applying this principle to the range of God’s actions: whatever God can conceive of, God can will—subject to the rules of logic. To will a thing and not will that same thing at the same time is of course logically contradictory, and putting God as the subject doesn’t change that.
Hence we are instructed in the rule of Catholic faith to profess that the Son is “consubstantial with the Father,” a phrase that excludes two errors. First, the Father and the Son may not be thought of according to carnal generation, which is effected by a certain separation of the son’s substance from the father. If this were so in God, the Son could not be consubstantial with the Father. Secondly, we are taught not to think of the Father and the Son according to intellectual generation in the way that a word is conceived in our mind. For such a word comes to our intellect by a sort of accidental accretion, and does not exist with the existence proper to the essence of the intellect.
When we go beyond negative things, then we can only speak analogously, as when we speak of God conceiving ideas in His intellect. The perfections of all things in creation, Thomas told us in Chapter 22, have their source and existence in God; or to put it another way, each creature is a mirror of God in its own way. The thing in God of which it is a reflection is not the same, but neither is it wholly different: there is a likeness. And thus, we can reason analogously, and thereby understand dimly a piece of the truth about God.
Consequently, Thomas has described the “divine filiation” of the Second Person of the Trinity using the analogies of the conception of offspring and the conception of ideas, but he hastens to insist that we not take these analogies too far.
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