  Bentham's view was surprising to many at the time at least in part because he viewed the moral quality of an action to be determined instrumentally. It isn't so much that there is a particular kind of action that is intrinsically wrong; actions that are wrong are wrong simply in virtue of their effects, thus, instrumentally wrong. This cut against the view that there are some actions that by their very nature are just wrong, regardless of their effects.  Some may be wrong because they are ‘unnatural’ — and, again, Bentham would dismiss this as a legitimate criterion. Some may be wrong because they violate liberty, or autonomy. Again, Bentham would view liberty and autonomy as good — but good instrumentally, not intrinsically. Thus, any action deemed wrong due to a violation of autonomy is derivatively wrong on instrumental grounds as well. This is interesting in moral philosophy — as it is far removed from the Kantian approach to moral evaluation as well as from natural law approaches. It is also interesting in terms of political philosophy and social policy. On Bentham's view the law is not monolithic and immutable.  Since effects of a given policy may change, the moral quality of the policy may change as well. Nancy Rosenblum noted that for Bentham one doesn't simply decide on good laws and leave it at that: “Lawmaking must be recognized as a continual process in response to diverse and changing desires that require adjustment” (Rosenblum 1978, 9). A law that is good at one point in time may be a bad law at some other point in time. Thus, lawmakers have to be sensitive to changing social circumstances.  To be fair to Bentham's critics, of course, they are free to agree with him that this is the case in many situations, just not all — and that there is still a subset of laws that reflect the fact that some actions just are intrinsically wrong regardless of consequences. Bentham is in the much more difficult position of arguing that effects are all there are to moral evaluation of action and policy.