Intention and Permissibility: Jonathan DancyScanlon's Principles

My first four sections concentrate on the second section of Professor Scanlon's contribution (hereafter IP ), where he lays out his conception of moral principles and of the role they play in theory and practice. I will raise questions on the following issues:
1. Scanlon's initial introduction of the notion of a principle.
2. His rejection of the standard view that principles are concerned with the forbidding, permitting and requiring of actions.
3. His rejection of pro tanto conceptions of principles in favour of a conception of them as conclusive.
4. The resulting account of what it is for a principle to face and survive exceptions.
Scanlon's discussion of these matters here both appeals to and is in some respects more detailed than the relevant section of his recent What We Owe to Each Other (hereafter WWO ). The topic is interesting both for the role played by principles in Scanlon's present discussion of intention and permissibility, and more generally because of his account of wrongness:
an act is wrong iff it is ruled out by principles that nobody could reasonably reject.
The remainder of my contribution is concerned with the ostensible focus of IP , namely the relevance (if any) of agent-intentions to the permissibility of what is done.