 The primary fact is not the ego, but the elements (sensations)…The elements constitute the I. I have the sensation green, signifies that the element green occurs in a given complex of other elements (sensations, memories). When I cease to have the sensation green, when I die, then the elements no longer occur in the ordinary, familiar association. That is all. Only and ideal mental-economical unity, not a real unity, has ceased to exist. (Mach 1886: 23–24)