In the whole system of the world's creation one sees a blind impulse working like a kind of mechanism of the universe. This impulse is more apparent in living creatures, and its most pronounced form is agitation. If we study the lives of the lower creatures we find that they not only have a desire for food or a desire to move about with their mates; their first desire is to sleep. But besides this there is an inclination which manifests as agitation, and it is because of this agitation that the animals and birds fight among themselves. Their whole life is filled with that agitation. Furthermore, herbivorous animals are less agitated than carnivorous ones, while in the carnivorous animals there is more desire for fighting. The lion and the tiger are more inclined to fight than horses and cows, which shows that the herbivorous animals are a step more advanced than the carnivorous animals.