It is odd that a value/virtue that plays such a central role in dramatic literature has played such a small role in philosophical writing. There are probably a number of reasons, but I think that a predilection for a certain kind of individualism is a major one. Others might include the fashionability of consequentialism, the idea that loyalty has more to do with sentiment than reason, as well as its proneness to corruption. The revival of interest in virtue/character as distinct from rules/principles has also created space for a renewed, if hesitant, interest in loyalty.

I see loyalty - roughly perseverance in relational commitments despite the cost of such perseverance - as an important human value/virtue. Think of it as a kind of relational glue.

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.

From time to time I have wished to do more work in philosophy of religion, but the demands and challenges have been such that it needed more work than I had time for. I sneaked a chapter into my book on loyalty that touched on some issues in the area. Maybe in the future I will try responding to Philip Kitcher's excellent critique: Life After Faith: The Case for Secular Humanism - it gets closer to me than much of what is produced in the field.

Think of loyalty as a kind of relational glue.

My view of ethics and of its priority is connected to my view that we are fundamentally relational beings - both the product of human interactions, as well as committed as part of the expression of our own humanity to various social involvements. I see ethics as having two places in the maintenance of these relational activities - first as providing the basic coinage of our interactions qua humans and second as mediating the various roles we assume as humans.

In later years, when I started working in police ethics, I was professionally drawn back to the topic but as well was better able to see two sides to loyalty - its importance for certain central human relations such as friendships, but also its corruptibility in the sense that loyalty could be invoked against other moral constraints: it sometimes function as something of a moral Trojan horse, undermining other moral considerations.