When the relations between self and environment are considered, a duality is found; the attention of the observer can either be consciously directed to objects, or objects can attract conscious attention. Thus, a gun fired unexpectedly in one's immediate neighbourhood would probably attract one's attention, whereas a row of runners lined up for the race are all “attention” in readiness for the sound of the gun. This duality I shall attempt to put in terms of my fundamental equation H + L = T.