I would have to read this book at least one more time in order to feel confident about summarizing the conclusions the author reaches. However, here’s my impression after reading it once. As I understand her aims, Carol Rovane wants to clearly explain what relativism is with respect to science and ethics, and then determine whether we should endorse relativism with respect to either of those domains.

She begins by criticizing what she calls “the prevailing, consensus view” of relativism, which she says relies on the idea of disagreement. This is the idea that relativism arises “with a certain kind of disagreement that is said to be, first of all, ‘irresoluble’ [i.e. unsolvable], but also, second, ‘irresoluble’ for the specific reason that both parties are right” [15-16]. Rovane prefers defining relativism in terms of alternatives, which may or may not involve disagreement, and which are themselves explainable in terms of “normative insularity”.

According to Rovane, relativists believe that some alternative views in science or ethics are cut off from other scientific or ethical views. Logic neither “mandates, licenses or prohibits” inferences between them, so two people can hold alternative views about science or ethics and logic has nothing to say about the alternatives [94]. It’s as if, metaphorically speaking, people can occupy different scientific or ethical worlds. Non-relativists, on the other hand, believe that all truth bearers are logically related, either directly or indirectly. My scientific views aren’t insulated from your scientific views, and your ethical views aren’t insulated from mine. We all occupy the same scientific world and the same ethical world.

Rovane goes so far as to label the non-relativist and relativist positions in terms of how many “worlds” they mandate. What she calls “unimundialism” is the non-relativistic view that there is only one world (in which there is no “normative insularity” between propositions in science or ethics). “Multimundialism” is the relativistic view that there are many worlds (in which there is “normative insularity” between some scientific or ethical propositions). 

I think the conclusion she reaches is that scientific theories apply to a single world, so it’s best not to think of science in unimundial or non-relativistic terms. Reality is one, so alternative scientific theories can’t be equally correct. But unlike scientists, who all study the same world, people grow up and live their daily lives in various social conditions. These social conditions help determine which behavior is morally correct for them. Rovane thinks it’s fair to say, therefore, metaphorically speaking, that people inhabit different ethical worlds depending on their particular social conditions. Hence, multimundialism or relativism is an acceptable view with respect to ethics.

To help justify her relativistic conclusion regarding ethics, Rovane asks us to imagine two women. One woman was brought up in Europe or America and accepts the ethical importance of autonomy, i.e. every individual’s right to make their way in the world according to their own needs and desires while respecting the needs and desires of other people. The other woman was brought up in a village in India and sincerely believes she has an ethical obligation to obey her parents, even if it means giving up her right to pursue her own needs and desires.  Rovane argues that these two women live in very different ethical worlds. Their societies are so different when it comes to ethical issues that each woman is acting ethically, even though they are following very different paths and choosing to obey very different ethical principles.