The real is the present, conceived not as a mathematical point between the present and the past, but as the union of present and past in a duration or permanence that is at the same time change. Thus the past as past and the future as future do not exist at all, but are purely ideal; the past as living in the present and the future as germinating in the present are wholly real and indeed are just the present itself. It is because of the presence of these two elements in the present... that the present is a concrete and changing reality and not an empty mathematical point.