The notion is unfortunately widespread that the mystery of the Blessed Trinity is a mystery of mathematics, that is to say, of how one can equal three.
The plain Christian accepts the doctrine of the Trinity; the "advanced" Christian rejects it; but too often what is being accepted by the one and rejected by the other is that one equals three.
The believer argues that God has said it, therefore it must be true; the rejecter argues it cannot be true, therefore God has not said it.
A learned non-Catholic divine, being asked if he believed in the Trinity, answered, "I must confess that the arithmetical aspect of the Deity does not greatly interest me"; and if the learned can think that there is some question of arithmetic involved, the ordinary person can hardly be expected to know any better.
(i) Importance of the doctrine of the Trinity
Consider what happens when a believer in the doctrine is suddenly called upon to explain it — and note that unless he is forced to, he will not talk about it at all: there is no likelihood of his being so much in love with the principal doctrine of his Faith that he will want to tell people about it. Anyhow, here he is: he has been challenged, and must say something. The dialogue runs something like this:
Believer: "Well, you see, there are three persons in one nature."
Questioner: "Tell me more."
Believer: "Well, there is God the Father, God the Son, God the Holy Spirit."
Questioner: "Ah, I see, three gods."
Believer (shocked): "Oh, no! Only one God."
Questioner: "But you said three: you called the Father God, which is one; and you called the Son God, which makes two; and you called the Holy Spirit God, which makes three."
Here the dialogue form breaks down. From the believer's mouth there emerges what can only be called a soup of words, sentences that begin and do not end, words that change into something else halfway. This goes on for a longer or shorter time. But finally there comes something like: "Thus, you see, three is one and one is three." The questioner not unnaturally retorts that three is not one nor one three. Then comes the believer's great moment. With his eyes fairly gleaming he cries: "Ah, that is the mystery. You have to have faith."
Now it is true that the doctrine of the Blessed Trinity is a mystery, and that we can know it only by faith. But what we have just been hearing is not the mystery of the Trinity; it is not the mystery of anything, it is wretched nonsense. It may be heroic faith to believe it, like the man who
Wished there were four of 'emor it may be total intellectual unconcern - God has revealed certain things about Himself, we accept the fact that He has done so, but find in ourselves no particular inclination to follow it up. God has told us that He is three persons in one Divine nature, and we say "Quite so", and proceed to think of other matters - last week's Retreat or next week's Confession or Lent or Lourdes or the Church's social teaching or foreign missions. All these are vital things, but compared with God Himself, they are as nothing: and the Trinity is God Himself. These other things must be thought about, but to think about them exclusively and about the Trinity not at all is plain folly. And not only folly, but a kind of insensitiveness, almost a callousness, to the love of God. For the doctrine of the Trinity is the inner, the innermost, life of God, His profoundest secret. He did not have to reveal it to us. We could have been saved without knowing that ultimate truth. In the strictest sense it is His business, not ours. He revealed it to us because He loves men and so wants not only to be served by them but truly known. The revelation of the Trinity was in one sense an even more certain proof than Calvary that God loves mankind. To accept it politely and think no more of it is an insensitiveness beyond comprehension in those who quite certainly love God: as many certainly do who could give no better statement of the doctrine than the believer in the dialogue we have just been considering.
That he might believe more of 'em
How did we reach this curious travesty of the supreme truth about God? The short statement of the doctrine is, as we have heard all our lives, that there are three persons in one nature. But if we attach no meaning to the word person, and no meaning to the word nature, then both the nouns have dropped out of our definition, and we are left only with the numbers three and one, and get along as best we can with these. Let us agree that there may be more in the mind of the believer than he manages to get said: but the things that do get said give a pretty strong impression that his notion of the Trinity is simply a travesty. It does him no positive harm provided he does not look at it too closely; but it sheds no light in his own soul: and his statement of it, when he is driven to make a statement, might very well extinguish such flickering as there may be in others. The Catholic whose faith is wavering might well have it blown out altogether by such an explanation of the Trinity as some fellow Catholic of stronger faith might feel moved to give: and no one coming fresh to the study of God would be much encouraged.
(ii) "Person" and "Nature"
Let us come now to a consideration of the doctrine of the Blessed Trinity to see what light there is in it for us, being utterly confident that had there been no light for us, God would not have revealed it to us. There would be a rather horrible note of mockery in telling us something of which we can make nothing. The doctrine may be set out in four statements:
In the one divine Nature, there are three Persons - the Father, the Son, and the Holy Spirit.
The Father is not the Son, the Son is not the Holy Spirit, the Holy Spirit is not the Father: no one of the Persons is either of the others.
The Father is God, the Son is God, the Holy Spirit is God.
There are not three Gods but one God.
We have seen that the imagination cannot help here. Comparisons drawn from the material universe are a hindrance and no help. Once one has taken hold of this doctrine, it is natural enough to want to utter it in simile and metaphor - like the lovely lumen de lumine, light from light, with which the Nicene Creed phrases the relation of the Son to the Father. But this is for afterward, poetical statement of a truth known, not the way to its knowledge. For that, the intellect must go on alone. And for the intellect, the way into the mystery lies, as we have already suggested, in the meaning of the words "person" and "nature". There is no question of arithmetic involved. We are not saying three persons in one person, or three natures in one nature; we are saying three persons in one nature. There is not even the appearance of an arithmetical problem. It is for us to see what person is and what nature is, and then to consider what meaning there can be in a nature totally possessed by three distinct persons.
The newcomer to this sort of thinking must be prepared to work hard here. It is a decisive stage of our advance into theology to get some grasp of the meaning of nature and the meaning of person. Fortunately the first stage of our search goes easily enough. We begin with ourselves. Such a phrase as "my nature" suggests that there is a person, I, who possesses a nature. The person could not exist without his nature, but there is some distinction all the same; for it is the person who possesses the nature and not the other way round.
One distinction we see instantly. Nature answers the question what we are; person answers the question who we are. Every being has a nature; of every being we may properly ask, What is it? But not every being is a person: only rational beings are persons. We could not properly ask of a stone or a potato or an oyster, Who is it?
By our nature, then, we are what we are. It follows that by our nature we do what we do: for every being acts according to what it is. Applying this to ourselves, we come upon another distinction between person and nature. We find that there are many things, countless things, we can do. We can laugh and cry and walk and talk and sleep and think and love. All these and other things we can do because as human beings we have a nature which makes them possible. A snake could do only one of them - sleep. A stone could do none of them. Nature, then, is to be seen not only as what we are but as the source of what we can do.
But although my nature is the source of all my actions, although my nature decides what kind of operations are possible for me, it is not my nature that does them: I do them, I the person. Thus both person and nature may be considered sources of action, but in a different sense. The person is that which does the actions, the nature is that by virtue of which the actions are done, or, better, that from which the actions are drawn. We can express the distinction in all sorts of ways. We can say that it is our nature to do certain things, but that we do them. We can say that we operate in or according to our nature. In this light we see why the philosophers speak of a person as the center of attribution in a rational nature: whatever is done in a rational nature or suffered in a rational nature or any way experienced in a rational nature is done or suffered or experienced by the person whose nature it is.
Now at first sight it might seem that this examination of the meaning of person and nature has not got us far toward an understanding of the Blessed Trinity. For although we have been led to see a distinction between person and nature in us, it seems clearer than ever that one nature can be possessed and operated in only by one person. By a tremendous stretch, we can just barely glimpse the possibility of one person having more than one nature, opening up to him more than one field of operation. But the intellect feels baffled at the reverse concept of one nature being totally "wielded", much less totally possessed, by more than one person. Now to admit ourselves baffled by the notion of three persons in the one nature of God is an entirely honorable admission of our own limitation; but to argue that because in man the relation of one nature to one person is invariable, therefore the same must be the relation in God, is a defect in our thinking. It is indeed an example of that anthropomorphism, the tendency to make God in the image of man, which we have already seen hurled in accusation at the Christian belief in God.
Let us look more closely at this idea. Man is made in the image and likeness of God. Therefore it is certain that man resembles God. Yet we can never argue with certainty from an image to the original of the image: we can never be sure that because the image is thus and so, therefore the original must be thus and so. A statue may be an extremely good statue of a man. But we could not argue that the man must be a very rigidman, because the statue is very rigid. The statue is rigid, not because the man is rigid, but because stone is rigid. So also with any quality you may observe in an image: the question arises whether that quality is there because the original was like that or because the material of which the image is made is like that. So with man and God. When we learn anything about man, the question always arises whether man is like that because God is like that, or because that is the best that can be done in reproducing the likeness of God in a being created of nothing. Put quite simply, we have always to allow for the necessary scaling down of the infinite in its finite likeness.
Apply this to the question of one person and one nature, which we find in man. Is this relation of one-to-one the result of something in the nature of being, or simply of something in the nature of finite being? With all the light we can get on the meaning of person and of nature even in ourselves, we have seen that there is still much that is dark to us: both concepts plunge away to a depth where the eye cannot follow them. Even of our own finite natures, it would be rash to affirm that the only possible relation is one person to one nature. But of an infinite nature, we have no experience at all. If God tells us that His own infinite nature is totally possessed by three persons, we can have no grounds for doubting the statement, although we may find it almost immeasurably difficult to make any meaning of it. There is no difficulty in accepting it as true, given our own inexperience of what it is to have an infinite nature and God's statement on the subject; there is not difficulty, I say, in accepting it as true; the difficulty lies in seeing what it means. Yet short of seeing some meaning in it, there is no point in having it revealed to us; indeed, a revelation that is only darkness is a kind of contradiction in terms.
(iii) Three Persons - One God
Let us then see what meaning, - that is to say, what light, - we can get from what has been said so far. The one infinite nature is totally possessed by three distinct persons. Here we must be quite accurate: the three persons are distinct, but not separate; and they do not share the divine nature, but each possesses it totally.
At this first beginning of our exploration of the supreme truth about God, it is worth pausing a moment to consider the virtue of accuracy. There is a feeling that it is a very suitable virtue for mathematicians and scientists, but cramping if applied to operations more specifically human. The young tend to despise it as a kind of tidiness, a virtue proper only to the poor-spirited. And everybody feels that it limits the free soul. It is in particular disrepute as applied to religion, where it is seen as a sort of anxious weighing and measuring that is fatal to the impetuous rush of the spirit. But in fact, accuracy is in every field the key to beauty: beauty has no greater enemy than rough approximation. Had Cleopatra's nose been shorter, says Pascal, the face of the Roman Empire and so of the world would have been changed: an eighth of an inch is not a lot: a lover, you would think, would not bother with such close calculation; but her nose was for her lovers the precise length for beauty: a slight inaccuracy would have spoiled everything. It is so in music, it is so in everything: beauty and accuracy run together, and where accuracy does not run, beauty limps.
Returning to the point at which this digression started: we must not say three separate persons, but three distinct persons, because although they are distinct - that is to say, no one of them is either of the others - yet they cannot be separated, for each is what he is by the total possession of the one same nature: apart from that one same nature, no one of the three persons could exist at all. And we must not use any phrase which suggests that the three persons share the Divine Nature. For we have seen that in the Infinite there is utter simplicity, there are no parts, therefore no possibility of sharing. The infinite Divine Nature can be possessed only in its totality. In the words of the Fourth Council of the Lateran, "There are three persons indeed, but one utterly simple substance, essence, or nature."
Summarizing thus far, we may state the doctrine in this way: the Father possesses the whole nature of God as His Own, the Son possesses the whole nature of God as His Own, the Holy Spirit possesses the whole nature of God as His Own. Thus, since the nature of any being decides what the being is, each person is God, wholly and therefore equally with the others. Further, the nature decides what the person can do: therefore, each of the three persons who thus totally possess the Divine Nature can do all the things that go with being God.
All this we find in the Preface for the Mass on the Feast of the Holy Trinity: "Father, all-powerful and ever-living God, ... we joyfully proclaim our faith in the mystery of your Godhead ...: three Persons equal in majesty, undivided in splendor, yet one Lord, one God, ever to be adored in your everlasting glory."
To complete this first stage of our inquiry, let us return to the question which, in our model dialogue above, produced so much incoherence from the believer - if each of the three persons is wholly God, why not three Gods? The reason why we cannot say three Gods becomes clear if we consider what is meant by the parallel phrase, "three men". That would mean three distinct persons, each possessing a human nature. But note that, although their natures would be similar, each would have his own. The first man could not think with the second man's intellect, but only with his own; the second man could not love with the third's will, but only with his own. The phrase "three men" would mean three distinct persons, each with his own separate human nature, his own separate equipment as man; the phrase "three gods" would mean three distinct persons, each with his own separate Divine Nature, his own separate equipment as God. But in the Blessed Trinity, that is not so. The three Persons are God, not by the possession of equal and similar natures, but by the possession of one single nature; they do in fact, what our three men could not do, know with the same intellect and love with the same will. They are three Persons, but they are not three Gods; they are One God.