About the absence of presence and the presence of absence

“(...) while Eisenman was discoursing on the absence of presence and the presence of absence, a member of the audience, thinking it time to leave, stepped in front of the projector, his expanded shadow eclipsing the image of the slide for a few well-chosen moments, thus illustrating the absence of presence and the presence of absence in wonderfully concrete terms. Since it was made without words or writing it could be proposed as the most telling critique to date. The rest of the audience certainly rated it thus, though more for its explicitness than its intellectual content.”(From ‘Translations from Drawing to Building and Other Essays’, Not to be Used for Wrapping Purposes: A Review of the Exhibition of Peter Eisenman’s Fin d’Ou T Hou S, by Robin Evans, page 120)