Structurally I don't see a fundamental difference between what we may reasonably expect of police and doctors - though obviously the fact that doctors are generally pursuing life-saving activities and police may be engaged in life-threatening activities may lead to differences in how we construe the moral limits to their roles.

I grew up in a home in which loyalty to family was central to my father's outlook. Adolescent changes to my outlook (which set me against parental values) made me very critical of loyalty, reinforced by certain religious writers I found influential at that time. Harry Blamires, The Christian Mind. But I remained conflicted about loyalty.

Police do not work at the immediate direction of the communities they serve, but through their institutional connections. Police departments may develop structures, modi operandi, and cultures that are ethically problematic.

What we have to ask is this: what can we morally expect of and allow to people whom we deploy to fulfill this or that social role :police officer, school teacher, physician? This may sometimes lead to difficult social decisions - e.g. should police be permitted to illegally import drugs as part of a sting operation? In the end, I think "common - that is, critical - morality" should determine the limits of the police role.

My mother thought my inclinations would do well in Law, but I was too shy and deliberative - slowfooted - for that, so I determined to be an English and German high school teacher. In my first year of university I had one subject to "fill in" and chose philosophy against the advice of my counselor. My university teachers in English and German were totally uninspiring; philosophy was wonderful and my results showed it. I chose it and basically backed into a situation in which only a philosophy career seemed a viable option. I've never regretted it, but there was a lot of serendipity.

Whistleblowing constitutes a nice test case for the evaluation of loyalty. Loyalty also appears at the intersection of many major philosophical debates: general ones such as those between consequentialism and deontology, reason and feeling, virtue and principle, as well as more specific ones such as nationalism and patriotism, morality and obedience, particularism and universalism.

In separating out, say, legal and moral requirements, I tend to work with paradigms rather than strict divisions - eg, paradigmatically, legal requirements are jurisdictionally bound whereas ethical requirements are aspirationally universal; ethical requirements focus especially on intentions whereas legal requirements focus primarily on conduct; ethical requirements take priority over legal requirements; and so on.