Common sense divorces the world from the subject and the latter's thought from its body. In proceeding from the body and the perceived world to the cogito, our investigation has overturned this division and juxtaposition of the "external" and "internal" by showing them to be inseparable. We have seen that subjectivity cannot be detached from the body itself; that the latter, as a primordial project, is inextricably tied to the perceived world; and finally, that thought itself is never "pure" but rather, presupposes perceptual consciousness and remains inseverable from it. Thought, subjectivity, body and world are therefore mutually implicatory; they form a single comprehensive system in which each term can be equally designated as "inside" or "outside" — hence Merleau-Ponty was able to declare at the conclusion of the last chapter that "the world is wholly inside and I am wholly outside myself". In reflecting on the being of each aspect of the subject-world system, we have already encountered temporality at various points because perception, being inherently perspectival, is of its very nature temporal. Perception moreover requires the synthesis of the body itself; and this synthesis involves a spatiality and motility whose existence implies that of time.