In Moral Realism and the Foundations of Ethics, David Brink defends a version of moral realism that makes use of a coherentist epistemology. I argue that we have good reasons to prefer a coherentist epistemology in ethics, and that common arguments in favor of foundationalism and against coherentism fail. I conclude that only the multiple coherent systems (MCS) objection poses a serious threat to coherentism, and that there is a way of meeting this objection as it is traditionally construed. Doing so requires adding an explanatory requirement to coherentism: a coherent system must not only be coherent, but explain why it is coherent. Though I argue that the MCS objection fails as traditionally construed, I propose variants of the objection which apply specifically to coherentist moral realism. Based on the social intuitionist model of moral decision-making, I point to evidence which indicates that intuitive moral judgments are the cause of reasoned moral judgments. This raises two problems: "the problem of intransigence" and the "limited problem of intransigence." These two problems constitute MCS objections to coherentist moral realism. The first problem claims that coherentism itself might not be possible for actual human beings, and that even if people are capable of forming coherent systems of belief, these systems are necessarily radically divergent as a result of various cultural and sociological factors. The second problem is that the coherentist moral realist should not expect a single moral system to result from moral reasoning (even ideally), because all such systems will include intuitions which are immune to reasoning. I argue that these MCS objections must be overcome if coherentist moral realism is to be a viable option.