While I agree with the gist of your argument, I'd make the following point: It was science that disproved notions of human racial inferiority, phrenology, witc

While I agree with the gist of your argument, I'd make the following point: It was science that disproved notions of human racial inferiority, phrenology, witchcraft, and other social conventions that led to conditions of horrible oppression. So while one might argue that the scientist should only reason about facts and not about morality, there are cases when someone acting in any professional capacity might choose to speak out about a moral issue that their professional activities have given them insight into. For what constitutes a moral judgment on a complex issue but an average moral judgment applied to advanced knowledge of a subject? The key difference (in my opinion) is not in the area of moral judgment but that some humans have the courage to apply moral judgment to issues that they are uniquely able to understand and others do not (I recall we debated wikileaks here a few months ago :) So unlike your conclusion that moral activism is outside the professional boundaries of science and should thus be left to professional moralizers (clergy? politicians? the general public?) I'd argue that anyone who discovers a moral outrage in the course of his/her professional work should speak out about it, but should not overstretch his/her claim to authority, since that authority is narrow to his/her field and often the moral question is broader, etc.