Causality is never directly perceived, and cannot be, as Hume noted, differing in principle from the ordered behaviour of things according to so-called 'laws', and so is the instance in which the mind's construction of the world is most salient. This fact is masked by the degree to which we inhabit a technological world built by exploiting the laws governing, that is the reliable correlations of, things, and also by the contrary fact that causality in its subjective form is the only thing we directly experience, from so close in that again we are at a loss to say what it is.