> Those who don’t buy the jigsaw puzzle view of humanistic thought are unlikely to be convinced by Parfit’s ingenious version of moral monism. After all, why sh

> Those who don’t buy the jigsaw puzzle view of humanistic thought are unlikely to be convinced by Parfit’s ingenious version of moral monism. After all, why should we think that all genuine human ideals and values, such as equality, freedom, justice and compassion, must form part of some pre-ordained or constructible harmonious whole? The evidence would suggest otherwise: that is, that an irreducible conflict of ethical ideals and values is the unalterable human situation (past and present). Monists like Parfit perceive the undeniable fact of moral disagreement as an avoidable state of affairs and one that can be eliminated through the application of human reason. And moral monists also tend to believe, as Parfit unequivocally did, that the only coherent form of moral realism is moral monism ‑ in other words, that the only alternative to the view that there is a single, true morality is moral relativism, or its unblushing first cousin, moral nihilism, the philosophical view which denies the existence and possibility of objective moral values. I'm concerned that the reviewer, Johnny Lyons, is erroneously conflating what _is_ (descriptive) from what _should_ be (normative). Parfit surely recognizes what exists, descriptively; his project involves motivating a normative ethics. This criticism is so obvious (to philosophers at least) that I wonder if I'm missing something and/or misinterpreting Lyons.