or reason and words in general. Harris also spends some time describing how science might engage nuances and challenges of identifying the best ways for individuals and groups to improve their lives. Many of these issues are covered below. Philosophical case Although Harris's book discusses the challenges that a science of morality must face, he also mentions that his scientific argument is indeed philosophical. Furthermore, he says that this is the case for almost all scientific investigation. He mentions that modern science amounts to careful practice of accepted first philosophical principles like empiricism and physicalism. He also suggests that science has already very much settled on values in answering the question "what should I believe, and why should I believe it?". Harris says it should not be surprising that normative ethical sciences are, or would be, similarly founded on bedrock assumptions (basic norms). Harris says: The way he thinks science might engage moral issues draws on various philosophical positions like ethical realism (there are moral facts), and ethical naturalism (these facts relate to the physical world). Harris says a science of morality may resemble utilitarianism, but that the science is, importantly, more open-ended because it involves an evolving definition of well-being. Rather than committing to reductive materialism, then, Harris recognizes the arguments of revisionists that psychological definitions themselves are contingent on research and discoveries. Harris adds that any science of morality must consider everything from emotions and thoughts to the actual actions and their consequences. For Harris, moral propositions, and explicit values in general, are concerned with the flourishing of conscious creatures in a society. He argues, "Social morality exists to sustain cooperative social relationships, and morality can be objectively evaluated by that standard." Harris sees some philosophers' talk of strictly private morality as akin to unproductive discussion of a private, personal physics. "If philosophers want to only talk about some bizarrely unnatural private morality, they are just changing the subject". Harris also discusses how interchangeability of perspective might emerge as an important part of moral reasoning. He alludes to an "unpleasant surprise principle", where someone realizes they have been supporting an ineffective moral norm (e.g. reported cases of Jew-hunting Nazis discovering that they themselves were of Jewish descent). Science and moral truths Harris identifies three projects for science as it relates to morality: (1) explaining why humans do what they do in the name of morality (e.g., traditional evolutionary