<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hello Hans,<div><br><div><div>On 02 Feb 2017, at 16:32, Hans von Baeyer wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">Thank you Pedro for mentioning my new book. <div><br></div><div><div style="font-size:12.8px">Actually, there is a connection between my book and the curious tale. QBists look at the future as a web of interlaced personal, numerical probability estimates, with no certainties anchored in REAL mechanisms. The probability that CERN will blow up the world is small enough to be negligible for most people, but not for all. The thing QBists reject as <u>in principle </u>unattainable is ABSOLUTE certainty, which many lay people and some physicists (Einstein was among them) continue to long for.</div></div><div style="font-size:12.8px"><br></div></div></blockquote><div><br></div><div>I am not absolutely certain about this. (grin).</div><div><br></div><div>Nor am I sure that Einstein defended absolute certainty (an epistemological notion). He defended determinism (a metaphysical or theological notion), which is neutral on what human or other creature can know, believe, know-for-sure or predict, .... </div><div><br></div><div>If we discard, like Feynman, the reduction of the wave postulate in quantum mechanics, we come back to a purely deterministic physics, but this does not enforce *any* certainty for any human, at least concerning physical prediction.</div><div><br></div><div>I tend to think that in the tiny "constructive" part of arithmetic (known as sigma_1 arithmetic: it allows only existential quantifiers), we can have something akin to certainty. It is hard to doubt that 3+4 = 7, for example, or that it exists some number n such that n + 4 = 7.</div><div><br></div><div>Bruno</div><div><br></div><div><br></div><div><br></div><div><br></div><br><blockquote type="cite"><div dir="ltr"><div style="font-size:12.8px">Hans Christian von Baeyer</div><div><br></div></div> _______________________________________________<br>Fis mailing list<br><a href="mailto:Fis@listas.unizar.es">Fis@listas.unizar.es</a><br>http://listas.unizar.es/cgi-bin/mailman/listinfo/fis<br></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><a href="http://iridia.ulb.ac.be/~marchal/">http://iridia.ulb.ac.be/~marchal/</a></div><div><br class="webkit-block-placeholder"></div></div></span><br class="Apple-interchange-newline"> </div><br></div></body></html>