Survival of self, of species, and of environment, these are what drive humans.
You can observe how the order of importance changes in a lifetime. What are
the things of immediate concern at a given age? Weather? The state of the d
igestion? Does she (or he) really care? All of those various hungers that fl
esh can sense and hope to satisfy. What else could possibly matter?

-Leto II to Hwi Noree, His Voice: Dar-es-Balat