I answer that, While in all creatures there is some kind of likeness to God, in the rational creature alone we find a likeness of "image" as we have explained above (Articles [1],2); whereas in other creatures we find a likeness by way of a "trace." Now the intellect or mind is that whereby the rational creature excels other creatures; wherefore this image of God is not found even in the rational creature except in the mind; while in the other parts, which the rational creature may happen to possess, we find the likeness of a "trace," as in other creatures to which, in reference to such parts, the rational creature can be likened. We may easily understand the reason of this if we consider the way in which a "trace," and the way in which an "image," represents anything. An "image" represents something by likeness in species, as we have said; while a "trace" represents something by way of an effect, which represents the cause in such a way as not to attain to the likeness of species. For imprints which are left by the movements of animals are called "traces": so also ashes are a trace of fire, and desolation of the land a trace of a hostile army.
Therefore we may observe this difference between rational creatures and others, both as to the representation of the likeness of the Divine Nature in creatures, and as to the representation in them of the uncreated Trinity. For as to the likeness of the Divine Nature, rational creatures seem to attain, after a fashion, to the representation of the species, inasmuch as they imitate God, not only in being and life, but also in intelligence, as above explained (Article [2]); whereas other creatures do not understand, although we observe in them a certain trace of the Intellect that created them, if we consider their disposition. Likewise as the uncreated Trinity is distinguished by the procession of the Word from the Speaker, and of Love from both of these, as we have seen (Question [28], Article [3]); so we may say that in rational creatures wherein we find a procession of the word in the intellect, and a procession of the love in the will, there exists an image of the uncreated Trinity, by a certain representation of the species. In other creatures, however, we do not find the principle of the word, and the word and love; but we do see in them a certain trace of the existence of these in the Cause that produced them. For in the fact that a creature has a modified and finite nature, proves that it proceeds from a principle; while its species points to the (mental) word of the maker, just as the shape of a house points to the idea of the architect; and order points to the maker's love by reason of which he directs the effect to a good end; as also the use of the house points to the will of the architect. So we find in man a likeness to God by way of an "image" in his mind; but in the other parts of his being by way of a "trace."
