Abstract: The book is a work in metaethics, constituting a defense of moral realism. The book begins with what I call a “modest transcendental argument” for the existence of the property of moral goodness based on an acknowledgment of the possibility that personal moral failing may go forever undetected; as such this is an argument from error. The property of physical health, understood in terms of proper function, is used as a model for moral goodness. This anchors the moral ontology on foundations as solid as those found in the physical sciences. A moral epistemology is developed in which we may learn about goodness much in the way doctors and scientists may learn about healthiness. The semantics that emerges from this picture is multifaceted and nuanced enough to preserve complicated common sense semantic intuitions about how the word “good” is used in moral contexts. The position also implies a defense of an externalist theory about the relationship between the recognition of a moral consideration and motivation. The book closes with an appendix in which the reduction of thermodynamics to statistical mechanics is questioned, and a nonreducible ontology for entropy is considered as an ontological model for both physical health and moral goodness.

Keywords: argument from error, Paul Bloomfield, entropy, ethics, externalism, healthiness, metaethics, moral epistemology, moral goodness, moral realism, moral semantics, ontology, philosophy, proper function, reduction