Geez-- couldn't Robert Greene have advised his readers to guard their reputation without suggesting that they should also try to trash somebody else's name? He was almost making sense, there, for a minute. You know, we are very flexible critters. We can be soul-dead savages, shockingly cruel, or Sister Teresa, devoted to helping wretched people who couldn't possibly return the favor. The most amazing thing is the amount of agency we have in the shaping of our own character. I think I would probably argue, chapter by chapter, that the author's opinion of what constitutes power is, in real life, pretty destructive in the long term.