Husserl suggested, on the notion of a horizon. When you open your eyes to the world, objects always offer themselves against a background, and this background, as you proceed further into the world which surrounds us, continually displaces itself rather as the horizon does for a sailor, without ever resolving itself into a final and impassable background. Thus, from background to background, from horizon to horizon, you can never succeed in grasping on to anything which you can hold as a final entity, a supreme Being or a first cause which might guarantee the real in which we are immersed.
