"Here the focus turns to the curious problem of presence-absence, which haunts research on systems of significations. A system or sub-system, whether of objects or words, both is and is not self-sufficient. It is self sufficient; it is complete whole. Each element refers to all others. It looks as full as an egg. Look at it a bit longer and a bit more closely: see, it empties itself. A host of questions, posed technically by linguists and tragically by philosophers, now arises. We ask: Who? For whom? Why? How? The system is not self-sufficient. This 'whole' is partial and open. It refers to 'something else': purpose on the on hand, and the 'subject', on the other, and beyond these two terms lies the totality and the meaning. (,,,)"
_ Henri Lefebvre, "Preface to the study of the Habitat of the 'Pavillon'" in "Lefebvre: Key Writings" (Continuum; NY, London; 2003) p. 132.