Objection 1. It would seem that in the state of innocence Adam had no mastership over the animals. For Augustine says (Gen. ad lit. ix, 14), that the animals were brought to Adam, under the direction of the angels, to receive their names from him. But the angels need not have intervened thus, if man himself were master over the animals. Therefore in the state of innocence man had no mastership of the animals.
Objection 2. Further, it is unfitting that elements hostile to one another should be brought under the mastership of one. But many animals are hostile to one another, as the sheep and the wolf. Therefore all animals were not brought under the mastership of man.
Objection 3. Further, Jerome says [The words quoted are not in St. Jerome's works. St. Thomas may have had in mind Bede, Hexaem., as quoted in the Glossa ordinaria on Genesis 1:26: "God gave man mastership over the animals, although before sin he had no need of them: for God foresaw that after sin animals would become useful to man." Therefore, at least before sin, it was unfitting for man to make use of his mastership.
Objection 4. Further, it is proper to a master to command. But a command is not given rightly save to a rational being. Therefore man had no mastership over the irrational animals.
On the contrary, It is written (Genesis 1:26): "Let him have dominion over the fishes of the sea, and the birds of the air, and the beasts of the earth" [Vulg."and the whole earth"].
I answer that, As above stated (95, 1) for his disobedience to God, man was punished by the disobedience of those creatures which should be subject to him. Therefore in the state of innocence, before man had disobeyed, nothing disobeyed him that was naturally subject to him. Now all animals are naturally subject to man. This can be proved in three ways.
First, from the order observed by nature; for just as in the generation of things we perceive a certain order of procession of the perfect from the imperfect (thus matter is for the sake of form; and the imperfect form, for the sake of the perfect), so also is there order in the use of natural things; thus the imperfect are for the use of the perfect; as the plants make use of the earth for their nourishment, and animals make use of plants, and man makes use of both plants and animals. Therefore it is in keeping with the order of nature, that man should be master over animals. Hence the Philosopher says (Polit. i, 5) that the hunting of wild animals is just and natural, because man thereby exercises a natural right.
Secondly, this is proved by the order of Divine Providence which always governs inferior things by the superior. Wherefore, as man, being made to the image of God, is above other animals, these are rightly subject to his government.
Thirdly, this is proved from a property of man and of other animals. For we see in the latter a certain participated prudence of natural instinct, in regard to certain particular acts; whereas man possesses a universal prudence as regards all practical matters. Now whatever is participated is subject to what is essential and universal. Therefore the subjection of other animals to man is proved to be natural.
Reply to Objection 1. A higher power can do many things that an inferior power cannot do to those which are subject to them. Now an angel is naturally higher than man. Therefore certain things in regard to animals could be done by angels, which could not be done by man; for instance, the rapid gathering together of all the animals.
Reply to Objection 2. In the opinion of some, those animals which now are fierce and kill others, would, in that state, have been tame, not only in regard to man, but also in regard to other animals. But this is quite unreasonable. For the nature of animals was not changed by man's sin, as if those whose nature now it is to devour the flesh of others, would then have lived on herbs, as the lion and falcon. Nor does Bede's gloss on Genesis 1:30, say that trees and herbs were given as food to all animals and birds, but to some. Thus there would have been a natural antipathy between some animals. They would not, however, on this account have been excepted from the mastership of man: as neither at present are they for that reason excepted from the mastership of God, Whose Providence has ordained all this. Of this Providence man would have been the executor, as appears even now in regard to domestic animals, since fowls are given by men as food to the trained falcon.
Reply to Objection 3. In the state of innocence man would not have had any bodily need of animals--neither for clothing, since then they were naked and not ashamed, there being no inordinate motions of concupiscence--nor for food, since they fed on the trees of paradise--nor to carry him about, his body being strong enough for that purpose. But man needed animals in order to have experimental knowledge of their natures. This is signified by the fact that God led the animals to man, that he might give them names expressive of their respective natures.
Reply to Objection 4. All animals by their natural instinct have a certain participation of prudence and reason: which accounts for the fact that cranes follow their leader, and bees obey their queen. So all animals would have obeyed man of their own accord, as in the present state some domestic animals obey him.
Source: Summa Theologica (New Advent)