Article 13 — Whether any being that is from another can be eternal

The thirteenth point of inquiry is whether any being that is from another can be eternal. (Parallel texts: ST I.42.2; In III Sent. 11.1; Compendium theologiae, ch. 43; Commentary on John, ch. 1, lect. 1.)

Obj. 1: And it seems that it cannot. For nothing that always is, needs something so that it might be. But everything that is from something needs that from which it is, so that it might be. Therefore, nothing that is from another always exists.

Obj. 2: Nothing receives what it has already. Now, that which always exists always has being; and hence, that which always exists does not receive being. But everything that is from another receives its being from that whence it is. Therefore, nothing that is from another always exists.

Obj. 3: That which exists already is not generated, nor does it come to be, nor is it in any way brought into being; for whatsoever is coming to be is not yet. Consequently, everything that is generated, or comes to be, or is produced must at one time not have been. Now, such is whatever is from another. Therefore, whatever is from another at some time is not. But that which at some time is not, does not always exist. Therefore, nothing that is from another is eternal.

Obj. 4: That which does not have being save from another, considered in itself does not exist. And such a thing must not exist at some time. Therefore, whatsoever is from another must at some time not have been, and consequently it is not eternal.

Obj. 5: Every effect is posterior to its cause. Now, that which is from another is the effect of that from which it is. Therefore, it is posterior to that from which it is, and thus, it cannot be eternal.

On the contrary, according to Hilary, that which from eternity was born of the Father has eternal being from his birth. (Hilary of Poitiers, On the Trinity 12.21 (PL 10:416).) Now, the Son of God was born of the eternal Father. Therefore, his birth is from eternity, and consequently, he is eternal.

I answer that, since we affirm that the Son of God proceeds from the Father naturally, it follows that he must proceed from the Father in such wise as to be coeternal with him. This may be made clear as follows.

There is this difference between will and nature: that nature is determined to one thing, both as regards what is produced by the power of nature and as regards its producing or not producing, whereas the will is found not to be determined in either respect. Yet someone can, by his will, do this or that, for instance, an artisan can make a bench or a box, and again make them and cease from making them, whereas a fire cannot but heat if the subject of its action be present, nor can it produce in matter any effect other than its like.

Consequently, although it may be said of creatures, which proceed from God by his will, that he could make a creature of this or that sort, and at this or that time, this cannot be said of the Son, who proceeds naturally. For the Son according to nature could not be of a different mode than the nature of the Father possesses. Nor could the Son be sooner or later in relation to the Father’s nature. For it cannot be said that the divine nature was ever lacking in natural perfection, by the advent of the power of which nature God’s Son has been begotten; for the divine nature is simple and unchangeable. Nor can it be said that this begetting was delayed through an absence or indisposition of matter, seeing that this begetting is altogether unchangeable. It follows, then, since the Father’s nature is eternal, the Son was also begotten of the Father from eternity, and consequently, he is coeternal with the Father.

The Arians, through holding that the Son does not proceed naturally from the Father, used to say that, like other things that proceed from God according to the decree of his will, he was neither coequal nor coeternal with the Father. However, the difficulty of regarding the begetting of the Son as coeternal with the Father arose from the habituation of knowledge in its consideration of the production of natural things, in which one reality is produced by another through movement. Now, a reality brought into being through movement begins to be, at the beginning, before being at the end of the movement. But since the beginning of a movement must precede the end by a duration, on account of movement implying succession, and again since movement cannot have a beginning or start without a moving cause to produce it, it is necessary that the moving cause in the production of anything must precede in duration that which it produces.

Consequently, that which proceeds from another without movement is, in duration, simultaneous with that from which it proceeds, such as the brilliance of a fire or the sun; for the brilliance of light proceeds from a luminous body suddenly and not gradually, since illumination is not a movement but the terminus of a movement. It follows, then, that in God, in whom there is absolutely no movement, the one proceeding is simultaneous with him from whom he proceeds, and thus, since the Father is eternal, the Son and the Holy Spirit, who proceed from him, are coeternal with him.

Reply Obj. 1: If “need” denotes a defect or lack of what is needed, then that which always exists does not need something so that it might exist. But if it denotes only the order of origin in reference to that whence a thing exists, nothing hinders a thing that always exists from needing something so that it might exist, insofar as it has being not from itself but from another.

Reply Obj. 2: Before receiving something, the recipient does not have it; rather, he has it when he has received it. Whence if he receives it from eternity, he has it from eternity.

Reply Obj. 3: This argument applies to generation in which there is movement, since that which is being moved to existence does not exist. And this is true in the sense that what is being generated is not, while what has been generated, is. Consequently, where there is no distinction between being generated and having been generated, it does not follow that what is generated at some time does not exist.

Reply Obj. 4: What has its being from another is not a being when considered in itself, if it be something other than the very being that it receives from another; however, if it is the very being that it receives from another, then considered in itself it cannot be a non-being, for it is not possible to consider non-being in being, although in what is other than being it can be considered. For that which exists can have something mixed with it, but being itself cannot, according to Boethius in De Hebdomadibus. (Boethius, Hebdomads 4, ln. 35 (PL 64:1311).) The first condition applies to creatures, the second to the Son of God.

Reply Obj. 5: The Son of God cannot be called an effect, because he does not come to be, but is begotten. For that is said to come to be whose being is distinct from its maker. Therefore, neither can the Father be called the cause of the Son, properly speaking, but his principle. Nor is it necessary for every cause to precede its effect in its duration, but only by priority of nature, as is clear in the case of the sun and its shining.