  In April 2016, Daniela Frauchiger and Renato Renner published an article
online in which they introduce a Gedankenexperiment that led them to conclude
that single-world interpretation of quantum theory cannot be self-consistent.
In a new version of the paper, published in September 2018, the authors
moderate their original claim by concluding that quantum theory cannot be
extrapolated to complex systems, at least not in a straightforward manner. The
purpose of this article is to offer a careful reconstruction of the F-R
argument, which allows us to show that: (i) the argument can be more clearly
formulated with no reference to what subjects know or see, but rather only in
terms of quantum propositions, (ii) in contrast to what some commentators
suppose, the argument does not require the hypothesis of collapse to arrive to
its conclusion, and (iii) the contradiction resulting from the F-R argument is
inferred by making classical conjunctions between different and incompatible
contexts. On the basis of this clarification, we will finally argue that the
conclusion of the F-R argument is not as novel and original as its great impact
might make us to suppose.
