 The argument goes as follows: if one triggers the apparatus with a superposition of two spin states, since only a few atoms are excited, since the excitations involve displacements which are smaller than the characteristic localization distance of GRW, since GRW does not induce reductions on photon states and, finally, since the photon states immediately overlap, there is no way for the spontaneous localization mechanism to become effective in suppressing the ensuing superposition of the states ‘photons emerging from point \(A\) of the screen’ and ‘photons emerging from point \(B\) of the screen’. On the other hand, since the visual perception threshold is quite low (about 6–7 photons), there is no doubt that the naked eye of a human observer is sufficient to detect whether the luminous spot on the screen is at \(A\) or at \(B\). The conclusion follows: in the case under consideration no dynamical reduction can take place and as a consequence no measurement is over, no outcome is definite, up to the moment in which a conscious observer perceives the spot.