King et al. are concerned about our use of relative measures to gauge progress toward health equality in HIV mortality. Prior work by some of these same authors suggests,1 and we concur, that values and moral issues are involved and that explicit consideration of these is essential. Their comment is useful as it spurs us to think more deeply and provides an opportunity to report why, in this situation, relative measures more adeptly address moral concerns. To begin, consider a situation in which human knowledge concerning how to prevent or treat a disease is absent. We may find absolute or relative differences between groups but, as a society, we bear no culpability for these differences, as we cannot do anything about them. However, when we develop knowledge, our moral responsibility grows in proportion to our capacity to control disease and death. Once we gain a certain level of mastery, we bear responsibility for the consequences our actions have on patterns of human health.2 This simple but compelling moral standpoint is what leads us to prefer relative over absolute measures in the situation we studied.3 To understand, imagine a circumstance in which mortality rates for a disease are declining precipitously as a result of an advance in human knowledge. Imagine also that the absolute gap between an advantaged and a disadvantaged group remains constant over time. According to our moral argument, a gap of the same magnitude becomes more problematic as we gain control over the disease—it is more completely our responsibility. An absolute measure (rate difference) fails to reflect this moral position, suggesting instead that health inequalities remained constant over time. A relative measure, by contrast, coheres with our moral stance by showing a growing rate ratio over time. It correctly indicates that an absolute gap of the same magnitude becomes more morally reprehensible as we gain control. King et al. have done us a service by identifying problems in the interface between measures of health inequality and the moral and ethical issues that surround them. However, we found little guidance in their statements with respect to how to move toward solutions to the philosophical issues they identify, thereby necessitating a very modest de novo attempt on our part. Thus, while King et al.’s insights have utility for identifying problems and thereby facilitating a kind of policing of health inequalities researchers to ensure acknowledgment of those problems, providing a well-reasoned set of ethical principles connected to these problems is an issue that still lies before us.