  Physicians define death as the "irreversible" breakdown of all
brain-functions including brain-stem. By "irreversible" they mean a damage that
is beyond the human capacity to restore the patient's healthy state. In the
same line I propose to complete the definition of quantum physics in [1] by
Principle D (Detection): "Detection outcomes (like death) are ordinarily
irreversible and observer-independent". It is then argued that this principle
excludes generalization of quantum superposition to visible objects bearing
observer-dependent outcomes. However this exclusion is not absolute: It rather
means that "Schr\"{o}dinger's cat" and "Wigner's friend" should be considered
"miracle" narratives beyond the domain of science.
