Some forms of Kantianism put great weight on "what we can imagine” holding that this can be a source of insight into necessary connections. Thus various of Kant's arguments about space and time depend on the purported fact that it is impossible for us to imagine certain things: we can know, Kant claims, a priori that space has only three dimensions because we cannot imagine it as having more than three dimensions. History in the form of non-Euclidean geometry and modern physics has put paid to that particular line of argument, but in general we should beware of depending too much on "What we can imagine?,” especially in politics. As Nietzsche puts it somewhere, sometimes the fact that you can't imagine a situation in which things are very different from the way they are now is not an especially good argument for the claim that they must be as they now are, but, rather, represents a failure of your powers about which you should feel mildly apologetic.