The Christian
afterlife, when lions can be
petted by humans while sitting next to
a lamb, without fear of getting mauled. Since humans are of the animal kingdom, they will behave good too.
In the age of well-behaving animals, no strain of
bacteria would not make us sick, and
elephants wouldn't
trample children.
In the age of well-behaving animals, no one would bother going to war or steal from someone.
