  The best form of generalism, therefore, probably tries to do the whole thing in terms of contributory principles—principles that specify considerations that always count as contributory reasons. In this picture it is quite possible for there to be reasons on both sides. The classic example of such a theory is W. D. Ross’s theory of Prima Facie Duties (Ross 1930, ch. 2). This is just an attempt to put into good theoretical order our untutored intuitions that there are many different sorts of things that can make a difference to how we should act. There is a principle that says ‘Be just’, but this does not mean that all just actions are in fact right; it only means that the justness of an action counts in its favour, or that an action is the better for being just. Sadly, an action can be just but still wrong for other reasons. This means that it can sometimes be morally required of us that we act unjustly. If it is, there will be features of the situation that require it of us; perhaps we owe an enormous debt of gratitude, or perhaps by this unjust action we can save Holland from flooding.