This dissertation defends realist views in ethics against arguments advanced by ethical constructivists. Realists think that ethical truth obtains independently of any preferred perspective. That is, it is at bottom independent of whatever beliefs, desires, or other forms of commitment we have. Constructivists, in contrast, deny this. But this could mean different things, and there is currently no consensus on what constructivism involves exactly or how we ought to understand this dispute. Consequently, it has been difficult to evaluate the merits of constructivist arguments. This work attempts to remedy these deficiencies by developing a framework for both interpreting and evaluating the nature and scope of the constructivist's challenge. In the first two chapters, I address some of the larger interpretative disputes. In Chapter 1, I argue that there are two main ways of understanding constructivism. Each of these corresponds to the rejection of a particular commitment of realism. In Chapter 2, however, I argue that neither of these should be understood as representing a freestanding view in metaethics. Rather, each takes aim at a narrower target: viz., the realist's conception of ethical objectivity. The first type of constructivist challenge rejects realist claims about the nature of ethical objectivity; the second type accepts these but rejects claims about it scope. In the final three chapters, I evaluate these two versions of the challenge. In Chapter 3, I argue that if the constructivist rejects all stance-independent ethical truth, she commits herself to absurd results within ethical theory. This prompts me to consider more modest constructivist theses, ones that allow for some stanceindependent ethical truths but that also significantly restrict the scope that such truths play within an ethical theory. In Chapters 4 and 5, however, I argue that the best arguments for this more modest constructivism also fail because the ethical considerations they appeal to - i.e., moral rationalism and autonomy - can be equally accommodated by a robust moral realism.