On Rewards and Punishments (85-86)

But since there are also two classes of enemies—the one being men, who are so deliberately, out of covetousness; the other being beasts, who are not so out of any deliberate purpose, or through study, but as being endowed with a nature utterly alien to ours—we must proceed to speak of them both in turn, and we will take, in the first place, the beasts which are our natural enemies; for these are hostile not to one city, or to one nation, but to the whole race of mankind, and that too not for any definite or limited period of time, but for an indefinite and illimitable eternity.

Of these some fear man as their master, and crouch beneath him with an angry fear; others, again, being bold and fearless, watch their opportunity and are the first to begin the warfare and attack him; if they are weaker than he, by an ambush; and if they are stronger, openly.