Heinz von Foerster Quote

To remove these one had to account for an observer (that is at least for one subject):
(i) Observations are not absolute but relative to an observer's point of view (i. e., his coordinate system: Einstein);
(ii) Observations affect the observed so as to obliterate the observer's hope for prediction (i. e., his uncertainty is absolute: Heisenberg).
After this, we are now in the possession of the truism that a description (of the universe) implies one who describes it (observes it).

p.258 - Notes on an epistemology for living things, 1981