# Nicene and Post-Nicene Fathers: Series I/Volume III/Doctrinal Treatises of St. Augustin/On the Holy Trinity/Book IX/Chapter 4

Chapter 4.—The Three are One, and Also Equal, Viz The Mind Itself, and the Love, and the Knowledge of It. That the Same Three Exist Substantially, and are Predicated Relatively. That the Same Three are Inseparable. That the Same Three are Not Joined and Commingled Like Parts, But that They are of One Essence, and are Relatives.
4. But as there are two things (duo quædam), the mind and the love of it, when it loves itself; so there are two things, the mind and the knowledge of it, when it knows itself. Therefore the mind itself, and the love of it, and the knowledge of it, are three things (tria quædam), and these three are one; and when they are perfect they are equal. For if one loves himself less than as he is,—as for example, suppose that the mind of a man only loves itself as much as the body of a man ought to be loved, whereas the mind is more than the body,—then it is in fault, and its love is not perfect. Again, if it loves itself more than as it is,—as if, for instance, it loves itself as much as God is to be loved, whereas the mind is incomparably less than God,—here also it is exceedingly in fault, and its love of self is not perfect. But it is in fault more perversely and wrongly still, when it loves the body as much as God is to be loved. Also, if knowledge is less than that thing which is known, and which can be fully known, then knowledge is not perfect; but if it is greater, then the nature which knows is above that which is known, as the knowledge of the body is greater than the body itself, which is known by that knowledge. For knowledge is a kind of life in the reason of the knower, but the body is not life; and any life is greater than any body, not in bulk, but in power. But when the mind knows itself, its own knowledge does not rise above itself, because itself knows, and itself is known. When, therefore, it knows itself entirely, and no other thing with itself, then its knowledge is equal to itself; because its knowledge is not from another nature, since it knows itself. And when it perceives itself entirely, and nothing more, then it is neither less nor greater. We said therefore rightly, that these three things, [mind, love, and knowledge], when they are perfect, are by consequence equal.
5. Similar reasoning suggests to us, if indeed we can any way understand the matter, that these things [i.e. love and knowledge] exist in the soul, and that, being as it were involved in it, they are so evolved from it as to be perceived and reckoned up substantially, or, so to say, essentially. Not as though in a subject; as color, or shape, or any other quality or quantity, are in the body. For anything of this [material] kind does not go beyond the subject in which it is; for the color or shape of this particular body cannot be also those of another body. But the mind can also love something besides itself, with that love with which it loves itself. And further, the mind does not know itself only, but also many other things. Wherefore love and knowledge are not contained in the mind as in a subject, but these also exist substantially, as the mind itself does; because, even if they are mutually predicated relatively, yet they exist each severally in their own substance. Nor are they so mutually predicated relatively as color and the colored subject are; so that color is in the colored subject, but has not any proper substance in itself, since colored body is a substance, but color is in a substance; but as two friends are also two men, which are substances, while they are said to be men not relatively, but friends relatively.
6. But, further, although one who loves or one who knows is a substance, and knowledge is a substance, and love is a substance, but he that loves and love, or, he that knows and knowledge, are spoken of relatively to each other, as are friends: yet mind or spirit are not relatives, as neither are men relatives: nevertheless he that loves and love, or he that knows and knowledge, cannot exist separately from each other, as men can that are friends. Although it would seem that friends, too, can be separated in body, not in mind, in as far as they are friends: nay, it can even happen that a friend may even also begin to hate a friend and on this account cease to be a friend while the other does not know it, and still loves him. But if the love with which the mind loves itself ceases to be, then the mind also will at the same time cease to love. Likewise, if the knowledge by which the mind knows itself ceases to be, then the mind will also at the same time cease to know itself. Just as the head of anything that has a head is certainly a head, and they are predicated relatively to each other, although they are also substances: for both a head is a body, and so is that which has a head; and if there be no head, then neither will there be that which has a head. Only these things can be separated from each other by cutting off, those cannot.
7. And even if there are some bodies which cannot be wholly separated and divided, yet they would not be bodies unless they consisted of their own proper parts. A part then is predicated relatively to a whole, since every part is a part of some whole, and a whole is a whole by having all its parts. But since both part and whole are bodies, these things are not only predicated relatively, but exist also substantially. Perhaps, then, the mind is a whole, and the love with which it loves itself, and the knowledge with which it knows itself, are as it were its parts, of which two parts that whole consists. Or are there three equal parts which make up the one whole? But no part embraces the whole, of which it is a part; whereas, when the mind knows itself as a whole, that is, knows itself perfectly, then the knowledge of it extends through the whole of it; and when it loves itself perfectly, then it loves itself as a whole, and the love of it extends through the whole of it. Is it, then, as one drink is made from wine and water and honey, and each single part extends through the whole, and yet they are three things (for there is no part of the drink which does not contain these three things; for they are not joined as if they were water and oil, but are entirely commingled: and they are all substances, and the whole of that liquor which is composed of the three is one substance),—is it, I say, in some such way as this we are to think these three to be together, mind, love, and knowledge? But water, wine, and honey are not of one substance, although one substance results in the drink made from the commingling of them. And I cannot see how those other three are not of the same substance, since the mind itself loves itself, and itself knows itself; and these three so exist, as that the mind is neither loved nor known by any other thing at all. These three, therefore, must needs be of one and the same essence; and for that reason, if they were confounded together as it were by a commingling, they could not be in any way three, neither could they be mutually referred to each other. Just as if you were to make from one and the same gold three similar rings, although connected with each other, they are mutually referred to each other, because they are similar. For everything similar is similar to something, and there is a trinity of rings, and one gold. But if they are blended with each other, and each mingled with the other through the whole of their own bulk, then that trinity will fall through, and it will not exist at all; and not only will it be called one gold, as it was called in the case of those three rings, but now it will not be called three things of gold at all.