The libertines’ “superiority” comes from their awareness and manipulation of nature’s inherent cycle of creation and destruction , which turns birth into a tool for asserting control, reflecting the Sadean obsession with motherhood, feces, and violent domination—later dramatized by Pasolini on screen.

his sentence is saying that the libertines see themselves as “superior” because they understand what they consider the true essence of nature : that life (birth) inevitably leads to death or destruction. In other words, they believe that the natural cycle—creating life only to have it end—is something most people ignore, but they consciously use it... See more

The libertines believe that life itself is temporary and fleeting, so giving birth is not an innocent act—it’s a natural process that ultimately leads to decay and death .