13
Observe how complex is a mother's love for her children, which draws everything toward an emotion felt in her inmost parts.
14
Even unreasoning animals, as well as human beings, have a sympathy and parental love for their offspring.
15
For example, among birds, the ones that are tame protect their young by building on the housetops,
16
and the others, by building in precipitous chasms and in holes and tops of trees, hatch the nestlings and ward off the intruder.
17
If they are not able to keep the intruder away, they do what they can to help their young by flying in circles around them in the anguish of love, warning them with their own calls.