The in­ten­tion of this pa­per is to po­int out a tr­o­u­ble­so­me si­tu­a­tion in con­tem­po­rary Ser­bian on­to­lo­gi­cal ter­mi­no­logy, and al­so to in­di­ca­te the ways and pre-con­di­ti­ons in terms of hi­story of phi­lo­sophy, hi­story of lan­gu­a­ge and met­ho­do­logy in se­ar­ching for pos­si­ble so­lu­ti­ons. We are al­so trying to cast so­me light on the pr­o­blem of re­la­ti­on­ship bet­we­en lan­gu­a­ge and phi­lo­sop­hi­cal thin­king.

In this article, I investigate the UNBELIEVABLE similar ideas of Brukner’s article (2015) and my ideas (2002-2008) In this article, I investigate the UNBELIEVABLE similar ideas of Brukner’s article (2015) and my ideas (2002-2008) I emphasize that this paragraph is not from my works!! Instead of “objectivity of the ‘facts of the world’, I used EDWs! All the ideas from this paragraph (and the philosophical ideas referring to QM from this article, can be found in my works 2002-2008!

According to QBism, quantum states, unitary evolutions, and measurement operators are all understood as personal judgments of the agent using the formalism. Meanwhile, quantum measurement outcomes are understood as the personal experiences of the same agent. Wigner’s conundrum of the friend, in which two agents ostensibly have different accounts of whether or not there is a measurement outcome, thus poses no paradox for QBism. Indeed the resolution of Wigner’s original thought experiment was central to the development of QBist thinking. The (...) focus of this paper concerns two very instructive modifications to Wigner’s puzzle: One, a recent no-go theorem by Frauchiger and Renner, and the other a thought experiment by Baumann and Brukner. We show that the paradoxical features emphasized in these works disappear once both friend and Wigner are understood as agents on an equal footing with regard to their individual uses of quantum theory. Wigner’s action on his friend then becomes, from the friend’s perspective, an action the friend takes on Wigner. Our analysis rests on a kind of quantum Copernican principle: When two agents take actions on each other, each agent has a dual role as a physical system for the other agent. No user of quantum theory is more privileged than any other. In contrast to the sentiment of Wigner’s original paper, neither agent should be considered as in “suspended animation.” In this light, QBism brings an entirely new perspective to understanding Wigner’s friend thought experiments. (shrink)