4. Our opponents therefore say, in the first place, that justice will be confounded, and things immoveable be moved, if we extend what is just, not only to the rational, but also to the irrational nature; conceiving that not only Gods and men pertain to us, but that there is likewise an alliance between us and brutes, who [in reality] have no conjunction with us. Nor shall we employ some of them in laborious works, and use others for food, from a conviction that the association which is between us and them, in the same manner as that of some foreign polity, pertains to a tribe different from ours, and is dishonourable. For he who uses these as if they were men, sparing and not injuring them, thus endeavouring to adapt to justice that which it cannot bear, both destroys its power, and corrupts that which is appropriate, by the introduction of what is foreign. For it necessarily follows, either that we act unjustly by sparing them, or if we spare and do not employ them, that it will be impossible for us to live. We shall also, after a manner, live the life of brutes, if we reject the use which they are capable of affording. 5. For I shall omit to mention the innumerable multitude of Nomades and Troglodytæ, who know of no other nutriment than that of flesh; but to us who appear to live mildly and philanthropically, what work would be left for us on the earth or in the sea, what illustrious art, what ornament of our food would remain, if we conducted ourselves innoxiously and reverentially towards brutes, as if they were of a kindred nature with us? For it would be impossible to assign any work, any medicine, or any remedy for the want which is destructive of life, or that we can act justly, unless we preserve the ancient boundary and law. To fishes, savage beasts, and birds, devoid Of justice, Jove to devour each other Granted; but justice to mankind he gave[17]. _i.e._ towards each other. 6. But it is not possible for us to act unjustly towards those to whom we are not obliged to act justly. Hence, for those who reject this reasoning, no other road of justice is left, either broad or narrow, into which they can enter. For, as we have already observed, our nature, not being sufficient to itself, but indigent of many things, would be entirely destroyed, and enclosed in a life involved in difficulties, unorganic, and deprived of necessaries, if excluded from the assistance derived from animals. It is likewise said, that those first men did not live prosperously; for this superstition did not stop at animals, but compelled its votaries even to spare plants. For, indeed, what greater injury does he do, who cuts the throat of an ox or a sheep, than he who cuts down a fir tree or an oak? since, from the doctrine of transmigration, a soul is also implanted in these. These therefore are the principal arguments of the Stoics and Peripatetics. _The Arguments of the Epicureans, from Hermachus[18]._