Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1812.05549

QBism and the Ithaca Desiderata

Blake C. Stacey

Published Dec 13, 2018• 2 citations
arXivHTMLPDF

Abstract

In 1996, N. David Mermin proposed a set of desiderata for an understanding of quantum mechanics, the "Ithaca Interpretation". In 2012, Mermin became a public advocate of QBism, an interpretation due to Christopher Fuchs and Ruediger Schack. Here, we evaluate QBism with respect to the Ithaca Interpretation's six desiderata, in the process also evaluating those desiderata themselves. This analysis reveals a genuine distinction between QBism and the IIQM, but also a natural progression from one to the other.

DOI
10.48550/arxiv.1812.05549

Related papers

Why QBism is not the Copenhagen interpretation and what John Bell might have thought of it

N. David Mermin

Christopher Fuchs and Rüdiger Schack have developed a way of understanding science, which, among other things, resolves many of the conceptual puzzles of quantum mechanics that have vexed people for the past nine decades. They call it QBism. I speculate on how John Bell might have reacted to QBism, and I explain the many ways in which QBism differs importantly from the orthodox ways of thinking about quantum mechanics associated with the term "Copenhagen interpretation."

arXiv:1409.2454•Sep 8, 2014•1 citation

QBism AND LOCALITY IN QUANTUM MECHANICS

Michael Nauenberg

A critique to the article by C.A. Fuchs, N.D. Mermin, and R.Schack, "An introduction to QBism with and application to the locality of quantum mechanics" that appeared in Am. J. Phys. 82 (8), 749-754 (2014)

arXiv:1502.00123•American Journal of Physics•Feb 23, 2015•4 citations

Letters to David Mermin

Christopher A. Fuchs

September 1996, “Theorem II” I encountered your “Ithaca Interpretation” paper this morning on the quant-ph archive … and, I must say, I've been walking around with a nice feeling since. There are some things in it that I like very much! Your Theorem II (or a very slight variation of it) has indeed been proven before, by Bill Wootters. I'll attach the citations below along with part of a note Bill once sent me. (Interestingly, one can also make a cut between real, complex, and quaternionic Hilbert spaces based on such a theorem.) About your Theorem I, if I am not mistaken, it also has a history that predates the references you gave. I believe Richard Jozsa once told me that a fellow named Hadjisavvas found it well before HJW and Gisin. If you are interested you can contact Richard directly; his e-mail address is.… As I say, I enjoyed your paper very much! (Presently) I think my only point of departure in what you say is about the issue of “objective probability.” Carl Caves and I (in still another paper cited below which can be found on quant-ph, pp. 22–26 in particular) have advocated the view that even the probabilities of quantum theory should be interpreted in a Bayesian or subjective way. We prefer to say that it is the “indeterminism” of quantum mechanics that is “objective,” and not the probabilities themselves.

Cambridge University Press eBooks•Jan 6, 2011•0 citations

Foreword

N. David Mermin

On 18 September 1996 I received email that began Dear Dr. Mermin, I encountered your “Ithaca Interpretation” paper this morning on the quant-ph archive … and, I must say, I've been walking around with a nice feeling since. There are some things in it that I like very much! Although I didn't really know my correspondent, it was clear from what followed that he had thought hard – probably harder than I had – about many of the matters I was trying to address. His scholarship and intelligence were so evident that I started walking around with a nice feeling myself at having received unsolicited praise from so thoughtful a source. Little did I know that those heartwarming words of appreciation were just bait to lure me into a long critical exchange which, to my pleasure and enlightenment, has been going on ever since. A part of my subsequent education (there have also been several invariably instructive and delightful real-life meetings) can be found in Chapter 18 below. If Chris Fuchs (rhymes with “books”) did not exist then God would have been remiss in not inventing him. Foundations of quantum mechanics is a unique blend of poetry and analysis. Without the poetic vision the analysis tends to chase its own tail into more and more convoluted realms of intricate triviality. Without the analysis the poetry easily degenerates into self-indulgent doggerel.

Cambridge University Press eBooks•Jan 6, 2011•0 citations

Towards Better Understanding QBism

Andrei Yu. Khrennikov

Recently I posted a paper entitled "External observer reflections on QBism". As any external observer, I was not able to reflect all features of QBism properly. The comments I received from one of QBism's creators, C. A. Fuchs, were very valuable to me in better understanding the views of QBists. Some of QBism's features are very delicate and extracting them from articles of QBists is not a simple task. Therefore, I hope that the second portion of my reflections on QBism (or, strictly speaking, my reflections on Fuchs reflections on my earlier reflections) might be interesting and useful for other experts in quantum foundations and quantum information theory (especially, taking into account my previous aggressively anti-QBism position). In the present paper I correct some of my earlier posted critical comments on QBism. At the same time, other critical comments gained new validation through my recent deeper understanding of QBists views on a number of problems.

arXiv:1604.07766•Foundations of Science•Feb 21, 2017•16 citations

Why QBism is not the Copenhagen interpretation, lecture, Vienna, June 2014

N. David Mermin

Our students learn quantum mechanics the way they learn to ride bicycles (both very valuable accomplishments) without really knowing what they are doing. – J. S. Bell, letter to R. E. Peierls, 20/8/1980 I think we invent concepts, like “particle” or “Professor Peierls,” to make the immediate sense of data more intelligible. – J. S. Bell, letter to R. E. Peierls, 24/2/1983 I have the impression as I write this, that a moment ago I heard the bell of the tea trolley. But I am not sure because I was concentrating on what I was writing…. The ideal instantaneous measurements of the textbooks are not precisely realized anywhere anytime, and more or less realized, more or less all the time, more or less everywhere. – J. S. Bell, letter to R. E. Peierls, 28/1/1981 [1] For the past decade and a half Christopher Fuchs and Rüdiger Schack (originally in collaboration with Carlton Caves) have been developing a new way to think about quantum mechanics. Fuchs and Schack have called it Qbism [2]. Their term originally stood for “quantum Bayesianism.” But QBism is a way of thinking about science quite generally, not just quantum physics [3], and it is pertinent even when probabilistic judgments, and therefore “Bayesianism,” play no role at all. I nevertheless retain the term QBism, both to acknowledge the history behind it, and because a secondary meaning remains apt in the broader context: QBism is as big a break with 20th-century ways of thinking about science as cubism was with 19th-century ways of thinking about art. QBism maintains that my understanding of the world rests entirely on the experiences that the world has induced in me throughout the course of my life. Nothing beyond my personal experience underlies the picture that I have formed of my own external world. This is a statement of empiricism. But it is empiricism taken more seriously than most scientists are willing to do. To state that my understanding of the world rests on my experience is not to say that my world exists only within my head, as recent popularizations of QBism have wrongly asserted [4]. Among the ingredients from which I construct my picture of my external world is the impact of that world on my experience, when it responds to the actions that I take on it.

Cambridge University Press eBooks•Jan 5, 2016•0 citations
In 1996, N. David Mermin proposed a set of desiderata for an understanding of quantum mechanics, the "Ithaca Interpretation". In 2012, Mermin became a public advocate of QBism, an interpretation due to Christopher Fuchs and Ruediger Schack. Here, we evaluate QBism with respect to the Ithaca Interpretation's six desiderata, in the process also evaluating those desiderata themselves. This analysis reveals a genuine distinction between QBism and the IIQM, but also a natural progression from one to the other.
September 1996, “Theorem II” I encountered your “Ithaca Interpretation” paper this morning on the quant-ph archive … and, I must say, I've been walking around with a nice feeling since. There are some things in it that I like very much! Your Theorem II (or a very slight variation of it) has indeed been proven before, by Bill Wootters. I'll attach the citations below along with part of a note Bill once sent me. (Interestingly, one can also make a cut between real, complex, and quaternionic Hilbert spaces based on such a theorem.) About your Theorem I, if I am not mistaken, it also has a history that predates the references you gave. I believe Richard Jozsa once told me that a fellow named Hadjisavvas found it well before HJW and Gisin. If you are interested you can contact Richard directly; his e-mail address is.… As I say, I enjoyed your paper very much! (Presently) I think my only point of departure in what you say is about the issue of “objective probability.” Carl Caves and I (in still another paper cited below which can be found on quant-ph, pp. 22–26 in particular) have advocated the view that even the probabilities of quantum theory should be interpreted in a Bayesian or subjective way. We prefer to say that it is the “indeterminism” of quantum mechanics that is “objective,” and not the probabilities themselves.
On 18 September 1996 I received email that began Dear Dr. Mermin, I encountered your “Ithaca Interpretation” paper this morning on the quant-ph archive … and, I must say, I've been walking around with a nice feeling since. There are some things in it that I like very much! Although I didn't really know my correspondent, it was clear from what followed that he had thought hard – probably harder than I had – about many of the matters I was trying to address. His scholarship and intelligence were so evident that I started walking around with a nice feeling myself at having received unsolicited praise from so thoughtful a source. Little did I know that those heartwarming words of appreciation were just bait to lure me into a long critical exchange which, to my pleasure and enlightenment, has been going on ever since. A part of my subsequent education (there have also been several invariably instructive and delightful real-life meetings) can be found in Chapter 18 below. If Chris Fuchs (rhymes with “books”) did not exist then God would have been remiss in not inventing him. Foundations of quantum mechanics is a unique blend of poetry and analysis. Without the poetic vision the analysis tends to chase its own tail into more and more convoluted realms of intricate triviality. Without the analysis the poetry easily degenerates into self-indulgent doggerel.
Recently I posted a paper entitled "External observer reflections on QBism". As any external observer, I was not able to reflect all features of QBism properly. The comments I received from one of QBism's creators, C. A. Fuchs, were very valuable to me in better understanding the views of QBists. Some of QBism's features are very delicate and extracting them from articles of QBists is not a simple task. Therefore, I hope that the second portion of my reflections on QBism (or, strictly speaking, my reflections on Fuchs reflections on my earlier reflections) might be interesting and useful for other experts in quantum foundations and quantum information theory (especially, taking into account my previous aggressively anti-QBism position). In the present paper I correct some of my earlier posted critical comments on QBism. At the same time, other critical comments gained new validation through my recent deeper understanding of QBists views on a number of problems.
Our students learn quantum mechanics the way they learn to ride bicycles (both very valuable accomplishments) without really knowing what they are doing. – J. S. Bell, letter to R. E. Peierls, 20/8/1980 I think we invent concepts, like “particle” or “Professor Peierls,” to make the immediate sense of data more intelligible. – J. S. Bell, letter to R. E. Peierls, 24/2/1983 I have the impression as I write this, that a moment ago I heard the bell of the tea trolley. But I am not sure because I was concentrating on what I was writing…. The ideal instantaneous measurements of the textbooks are not precisely realized anywhere anytime, and more or less realized, more or less all the time, more or less everywhere. – J. S. Bell, letter to R. E. Peierls, 28/1/1981 [1] For the past decade and a half Christopher Fuchs and Rüdiger Schack (originally in collaboration with Carlton Caves) have been developing a new way to think about quantum mechanics. Fuchs and Schack have called it Qbism [2]. Their term originally stood for “quantum Bayesianism.” But QBism is a way of thinking about science quite generally, not just quantum physics [3], and it is pertinent even when probabilistic judgments, and therefore “Bayesianism,” play no role at all. I nevertheless retain the term QBism, both to acknowledge the history behind it, and because a secondary meaning remains apt in the broader context: QBism is as big a break with 20th-century ways of thinking about science as cubism was with 19th-century ways of thinking about art. QBism maintains that my understanding of the world rests entirely on the experiences that the world has induced in me throughout the course of my life. Nothing beyond my personal experience underlies the picture that I have formed of my own external world. This is a statement of empiricism. But it is empiricism taken more seriously than most scientists are willing to do. To state that my understanding of the world rests on my experience is not to say that my world exists only within my head, as recent popularizations of QBism have wrongly asserted [4]. Among the ingredients from which I construct my picture of my external world is the impact of that world on my experience, when it responds to the actions that I take on it.