Moral reasons for action exist, if they do exist, independently of whether we know about them or not. If I have a (conclusive) moral reason to perform a certain action, then, as a matter of fact, I ought to perform it. The ‘ought’ in question is a categorical one. The point is not that, if I want to be moral, I ought to perform this action (this would be a Humean reason for me to perform it). The point is that, irrespective of what I want, I ought to perform this action. The explanation of why I ought to perform this action is my moral reason to perform it. Some notion of a moral reason along these lines is common place. However, the definition here used was first put forward only recently by John Broome.¹ The idea that the notion of a conclusive moral reason is basic is my own, however. Broome does not share it. This idea fits nicely with a traditional covering law notion of an explanation in general, however. I will get back to this.