In my search for "dark thinkers" not afraid to probe, I discovered a pair of books by an Ernest Becker:
Denial of DeathEscape From Evilquote:
What are we to make of a creation in which the routine activity is for organisms to be tearing others apart with teeth of all types—biting, grinding flesh, plant stalks, bones between molars, pushing the pulp greedily down the gullet with delight, incorporating its essence into one's own organization, and then excreting with foul stench and gasses the residue.