Recent work in moral psychology that claims to show that human beings make moral judgements on the basis of multiple, divergent moral foundations has been influential in both moral psychology and moral philosophy. Primarily, such work has been taken to undermine monistic moral theories, especially those pertaining to the prevention of harm. Here, I call one of the most prominent and influential empirical cases for moral pluralism into question, namely that of Jonathan Haidt and his colleagues. I argue that Haidt (...) et al.’s argument is not as strong as it is often made out to be, given significant problems with the design of one of the key experiments used to ground the claim that there are divergent moral foundations across cultures. The flaws that I point out pose a significant challenge to Haidt et al.’s findings and have a detrimental impact on subsequent work based on this immensely influential experiment. Accordingly, I argue that both empirical and normative claims made on the basis of Haidt et al.’s findings should be treated with caution. I conclude by making some suggestions as to how some of the problems that I point out might be addressed. (shrink)