Stanley Fish suggests that philosophical questions such as that of Moral Relativism vs Moral Absolutism are essentially irrelevant in practical terms. Though I might agree with Fish’s take on philosophy about many other examples, this in particular is one where I do not. In fact I think that one’s position on that issue colours the attitude with which we approach the law – especially criminal law – and that a position of moral absolutism leads to an approach that I find offensive and which I suspect is counterproductive.
Another philosophical issue which impacts the law and how we apply it is that of Free Will. Primitive notions of responsibility can lead to application of punishment where it will do no good, and when doubts about the extent of our freedom arise, having founded the rationale for punishment on them can lead to a dangerous leniency which results from finding just about anything excusable. It would be helpful perhaps to identify “responsibility” just with what its etymology implies – namely the level of appropriate response to an offense – and to choose the response on the basis of what future effects it may have – in terms of restraining the offender, discouraging others from acting similarly, and mollifying the victims (all to be balanced against whatever pain or other harm that response causes to the offender).
This really does matter because bogus “philosophical” arguments do seem to be capable of persuading people to adopt legal positions that they would not otherwise have accepted.