“Ceci n’est pas le chat de Schrodinger, ceci est le chat de Piron.” (C. Piron)
Bob Coecke (Oxford) writes:
“It is with sadness that I report that Constantin Piron, famous for many things including the Jauch-Piron NoGo-theorem and his reconstruction theorem, and of course his beautiful book Foundations of Quantum Physics, has died at the age of 80. While usually associated with quantum logic, he strongly emphasized an operational underpinning of axiomatic concepts, and boldly went against any dogma, including quantum logic. He was probably the most colorful, entertaining, and especially the boldest scientist I ever have met, in many ways.”
Piron did his PhD (Lausanne 1963) on axiomatic quantum theory under the supervision of Josef-Maria Jauch and Ernst Stueckelberg, two other giants of the Swiss school on the foundations of quantum mechanics. For some anecdotes not illustrating Piron’s work, but his human side, go to this website. I have noticed, with shock, that there exists no Wikipedia page on him, at least not in English. Anybody who has reliable information about him is hereby invited to change this! Also, please feel free to comment on this post.
Taking up Spacetime 
Hi, I am planning to write something for the Quantum Times and this could be the start of a wiki. Thanks for posting this. -bob
Excellent idea! Let me know what comes of it.
I used several results of Constantin Piron in my papers on the Hilbert Book Model, which represents my personal view on Physics. In 1963 I started my studies on what is now called the Technical University of Eindhoven. I quickly became interested in the papers of the group around Jauch and Piron. The TUE concerns applied Physics and theoretical Physics was never a main target of that institute. So after my studies I joined high tech industry and worked on the development of image intensifiers. After my retirement I had enough time to spend on theoretical Physics and in 2009 I started a personal project with as target to investigate the undercrofts of physics. In 2011 the Hilbert Book Model emerged, which is a simple self-consistent model that is strictly based on quantum logic. I refined quantum logic into what I called Hilbert logic. Hilbert logic resembles a separable Hilbert space more than quantum logic does.
Piron once investigated what kind of propositions can be used in quantum logic. He concluded that these propositions must be formulated such that they can simply be answered with an affirmation or a negotiation. The Hilbert makes another choice. Hilbert propositions are characterized by a numeric value that represents the “strength” of the propositions. As a consequence linear combinations of Hilbert propositions can again be Hilbert propositions. I use Piron’s result that the inner products of Hilbert spaces must be specified with a member of a division ring. The strength of the Hilbert proposition must be taken from such a division ring.
This approach leads to a refreshing view of the undercrofts of physics. Especially it reveals what is below physical fields.