This article introduces two reasons for ecological realism. The first point is that information exists within the environment specifying the affordances of that environment for that observers. Given that ecological information is ambient or external, the process of picking up information becomes one of detection, not construction. An affordance is a potential resourse or special combinations of resources. It can, but it need not, become incorparated into a process. There is a difference between the environment of all animals and that of one animal. The theory of affordances implies that to perceive things is to perceive what to do or not to do with them. Successful action must be controlled prospectively by affordances. Information often appears well before the paticular informations are actually apprehended by the perceiver. This ‘unfilled meanings’ (Reed, 1996) control perceiver's exploratory action. We call this process as prospective control of action and this information predictive. The existence of this process also reveals the reasons for realism.