Does the idea of "conflict of interest" figure into any contemporary discussion of ethics in philosophy? For example, few would argue that a professor having a sexual relationship with a student in his class is immoral in itself, but why would that necessarily be a conflict of interest? Banning such relationships is what is immoral because it reduces people's humanity by presupposing that humans are totally unable to separate their private lives from their professional ones. Are we to ban family businesses too? Even if empirical studies DO show that a majority of these kinds of relationships result in preferential grading, universities can always discipline such professors--disciplining the student would certainly be excessive. Banning relationships are the worst kinds of bans as without relationships we are dehumanized; it seems to me that if a person personally wishes to jeopardize his career for the sake of a relationship, then we should acknowledge and accept that.