According to objectivism about the practical 'ought', what one ought to do depends on all the facts; according to perspectivism, it depends only on epistemically available facts. This essay presents a new argument against objectivism. The first premise says that it is at least sometimes possible for a normative theory to correctly guide action. The second premise says that, if objectivism is true, this is never possible. From this it follows that objectivism is false. Perspectivism, however, turns out to be compatible with the plausible assumption about guidance.  I defend the two premises on the basis of an account of what it is for a normative theory to guide action. Central to this account is the idea that correct action-guidanc...