It is a common idea that morality, or moral truths, if there are any, must have some sort of source, or grounding. It has also been claimed that constructivist theories in metaethics have an advantage over realist theories in that the former but not the latter can provide such a grounding. This paper has two goals. First, it attempts to show that constructivism does not in fact provide a complete grounding for morality, and so is on a par with realism in this respect. Second, it explains why it seems that morality in fact couldn’t have a source.