In their daily lives, human beings make decisions about what and how and why they want to do things. Sometimes such decisions are practical; for example, whether one walks to work or takes the train. On occasion such decisions are simply emotional ones; for example, whether one feels like wearing the red or the green dress to tonight's party. And sometimes they are ethical decisions; for example, deciding not to drink and drive. With each of these examples most people will agree that there are certain straightforward motives that explain why people make the decisions they do: it makes more sense; it feels better; it is 'the right thing to do', respectively.

On closer examination, however, one can see that such decisions are not as straightforward as they might at first appear. Walking to work can be a decision made for environmental as much as practical reasons. One might wear the red dress to avoid clashing with the hostess. And not drinking and driving is a very practical thing to do if one already has ten points on one’s driving licence. The reasons why we make certain decisions, therefore – even, perhaps especially, ethical ones – are complex. We might appeal to such concepts as justice, equality, freedom and civic consideration, but the ways in which such concepts justify or authorise our decisions always raise significant epistemological questions.1 That we normally answer these questions without too much thought does not mean that the questions disappear. It means, rather, that we are too often unreflective at just that point where we need to do most of our thinking.