Whether brute animals know friendship or enmity.
How the types of animal vary," etc. In this eighth book the Philosopher makes a determination regarding friendship or enmity among animals. This is why it is asked whether friendship and enmity are present in brute beasts.
1. It seems not. Those passions that surpass the sensible powers and operations are only present in those animals possessing a power that rises above sensation. But friendship and enmity surpass the sensible operations, and they are therefore not present in beasts.
2. Besides, friendship and enmity are not present in those whose operations are directed toward a single thing, because these exist with respect to multiple things. But the operations of brute beasts are directed toward a single thing, because they lack reason, which is capable of opposites; for this reason, etc.
The Philosopher says the opposite.
It should be said that friendship and enmity are found in brute animals. The reason for this is that friendship consists in the perception of what is agreeable and enmity in the perception of what is harmful. But these are found in brute animals, and therefore, etc. For birds perceive that a seed is agreeable to them, and a sheep or lamb perceives that a wolf is harmful to it but that a human or a shepherd is a friend.
1. On to the arguments. To the first argument one should respond that the sensitive power is doubleinternal and external. Sight, hearing, and the like are external; common sense and the imaginative, estimative, and recollective senses are internal. Thus, although friendship and enmity are not perceived by means of the external senses, nevertheless they are perceived by means of the estimative sense, because the estimative sense is properly perceptive of intentions undivided [from the percept], which do not fall under the purview of sense or which do not move sense per se.
2. To the second argument one must respond that although the power of brute beasts does not relate to contraries as contraries, as does reason or the will, nevertheless the power of brute animals does relate to diverse options: to one through choosing something, to another through avoidance of it.
Whether friendship and enmity are present in all brute animals.
Next one asks whether these are present in all brute animals.
1. It seems not. Friendship and enmity are not found among those in which the estimative sense is absent. But many brute beasts lack the estimative sense. For the first book of the Metaphysics says that the life of animals is ruled by sensation alone and a human's life is ruled by art and reason. Therefore, etc.
2. Besides, those possessing friendship and enmity perceive objects from a distance. But many animals, such as the immobile ones, lack sight, hearing, and smell; therefore, etc.
On the contrary: Every animal takes delight in that which is agreeable and is saddened by that which is harmful. But where there are grief, joy, and sadness there are also friendship and enmity. Therefore, etc.
It must be said that a certain natural agreement exists, and this is found among inanimate things, for example, between one fire and another, and one rock and another. Another agreement follows upon sensation, or is perceived through sense. Friendship consists in this type of agreement. Thus, even though one rock "agrees" with another, the rock does not, however, perceive that agreement. But there is no animal that does not perceive that which is agreeable to it and equally that which is harmful to it, because even immobile animals expand and flow out over agreeable things, but if they are touched by something harmful they contract, and thus, with natural instinct they are adjudging the former things as friendly and the latter things as hostile, etc.
-  The translation preferred reflects the ambiguity of the original Latin.