My understanding is basically there are two systems of thought: Man was made in god's image, or "by the gods", whatever your religion happens to be. We had a "fall" at some point, and now suffer from karma, or sin, going all the way back to the first man. And by submitting to organized religion, only they, and their system, can "purify" us of that original flaw or sin. The idea of a "more perfect beast" I think comes from Nietzche, and boils down to: man came from beasts, and now straddles something between being gods (relative to everything else on the planet) and being beasts--and yet being neither god nor beast. And that with each new age or civilization, each new rise in our global knowledge and scientific progress, we grow closer and closer to euphemistically-speaking being gods. This notion obliterates original sin, and harkens back to the idea tht nature is a work in progress, and that the world is knowable, and truth discernible. And carries with it some semblance of then notion of manifest destiny, or the greatness of mans past, present, and future achievements. I'd say the truth is probably somewhere in the middle, a synthesis of the two: Original sin supposes we were not flawed, but were damaged early on. Whatever the case, it carries with it the understanding that all creations, all systems tend to fail over time. While the idea of a more perfect beast, carries with it the understanding that improvement is an iterative process--which in itself carries explains all sorts of things like why revolutions fail and become the very things they fight, why utopianism fails, and so on.