It is a world of change in which we live, and a world of uncertainty. We live only by knowing something about the future. We often act then on partial knowledge when making decisions about the future. Conscious life can react to a situation before that situation materialises; it can “see things coming.” The role of consciousness is to give “knowledge” of the future. We perceive the world and make inferences before we react to it. The universal form of conscious behaviour is thus action designed to change a future situation inferred from a present one. It involves perception and, in addition, inference. We must infer what the future situation would have been without our interference. Unfortunately, none of these processes is infallible, or indeed ever accurate and complete. We do not perceive the present as it is and in its totality, nor do we infer the future from the present with any high degree of dependability, nor yet do we accurately know the consequences of our own actions.