Despite the title of the article by Preda and Voigt (2015), our view is that the article does not present a critique of why we should care about social factors affecting health. It is also not about a field of study, or a critique of a model, or a critique of a body of research. What the authors are criticizing is a position on social inequalities in health purportedly taken in a series of commissioned reports, including several chaired by Michael Marmot. The authors summarize this position as "health equity through social change" (HESC), but this model is the authors' own construction, which limits the reach of the author's critique, particularly the aspects directed at the assumptions about justice. The authors focus primarily on critiquing two aspects of the HESC model: the normative argument for action to reduce social inequalities in health and the policy recommendations proposed to achieve this. The article touches upon numerous issues worthy of discussion, but it is impossible to exhaustively cover them all here. In this peer commentary, we describe how social determinants of health research relates to social inequalities in health research. We then discuss the role of empirical evidence, which prompts us to question the authors' conclusion regarding the evidence for both the justification for reducing social inequalities in health and the work to address social determinants of health. We also note that the authors attempt to critique the evidence for social determinants of health, but not for individual autonomous decisions to impact health, and we believe that more useful conclusions can be drawn if evidence for each is considered in a more balanced manner.Study of the social determinants of health and study of the causes of social inequalities in health are two diverse fields that are producing useful empirical work that generally has the goal of improving health. Varying differentiations of social are used throughout these fields, and in the article, and it is important to realize the function of each for addressing their critiques of these fields. First, the social can be considered, as described in this article, as "the circumstances in which people are born, grow up, live, work and age, and the systems put in place to deal with illness. These circumstances are in turn shaped by a wider set of forces: economics, social policies, and politics" (World Health Organization [WHO] 2014). It is this definition of social, the broad, that is of relevance for determining whether social inequalities are unjust. In contrast, when discussing specific definitions of the social, for example, a particular measure of socioeconomic position, the causal effects of that factor must be demonstrated through a balance of evidence in order to justify action on that factor to improve health. That is, if the broad definition is used, then it is reasonable to assume that everything has social causes, but this is not true in if the narrow definition is used. We discuss in the following both types of evidence, that which answers...