Thursday, June 14, 2018

Rovelli defends ancient philosophy for physics

Carlo Rovelli writes Physics Needs Philosophy. Philosophy Needs Physics.
Against Philosophy is the title of a chapter of a book by one of the great physicists of the last generation: Steven Weinberg, Nobel Prize winner and one of the architects of the Standard Model of elementary particle physics. Weinberg argues eloquently that philosophy is more damaging than helpful for physics - although it might provide some good ideas at times, it is often a straightjacket that physicists have to free themselves from. More radically, Stephen Hawking famously wrote that "philosophy is dead" because the big questions that used to be discussed by philosophers are now in the hands of physicists. Similar views are widespread among scientists, and scientists do not keep them to themselves. Neil de Grasse Tyson, a well known figure in the popularisation of science in America, publicly stated in the same vein: ".we learn about the expanding universe, . we learn about quantum physics, each of which falls so far out of what you can deduce from your armchair that the whole community of philosophers . was rendered essentially obsolete."
That's right, many modern physicists have concluded that philosophy is dead to them.

Rovelli disagrees, but his argument is almost entirely based on Aristotle and other long-dead philosophers, and by arguing in favor of philosophical thinking.

His examples:
But the direct influence of philosophy on physics is certainly not limited to the birth of modern physics. It can be recognised in every major step. Take the twentieth century. Both major advances made by twentieth century physics were strongly influenced by philosophy. They would have been inconceivable without thephilosophy of the time. Quantum mechanics springs from an intuition due to Heisenberg, grounded in the strongly positivist philosophical atmosphere in which he found himself: one gets knowledge by restricting oneself to what is observable. The abstract of Heisenberg's 1925 milestone paper on quantum theory is explicit about this:

"The aim of this work is to set the basis for a theory of quantum mechanics based exclusively on relations between quantities that are in principle observable."

The same distinctly philosophical attitude nourished Einstein's discovery of special relativity: by restricting to what is observable, we recognise that the notion of simultaneity is misleading. Einstein explicitly recognised his debt to the philosophical writings of Mach and Poincaré. Without these inputs, his special relativity would have been inconceivable. Although not the same, the philosophical influences on Einstein's conception of general relativity were even stronger. Once again, he was explicit in recognising his debt to philosophy, this time to the critical thinking of Leibniz, Berkeley, and Mach.
That's right, the discoveries of relativity and quantum mechanics were strongly influenced by logical positivist thinking.

His history is not quite correct. Einstein did not discover special relativity or the problem of simultaneity. He got most of SR from Lorentz, and got synchronization from Poincare. Up to his dying day, he never acknowledged his debt to Poincare. Einstein did not really buy into the positivist philosophy, and disavowed positivist thinking about QM. He explicitly disavowed positivism in 1945.

I agree that logical positivism has been important to physics, but it has been a dead philosophy since WWII.

I defend logical positivism, but I am in very small minority. There are no reputable philosophers who defend it.

Post-WWII philosophers not only reject logical positivism, they reject the scientific method and much of what modern science is all about.

Siding with today's philosophers is essentially the same as being anti-science. Modern philosophy is at war with modern science.

The only philosophers of the last century discussed by Rovelli are Popper and Kuhn, and Rovellis concedes that they have had a negative influence on physics.
I suspect that part of the problem is precisely that the dominant ideas of Popper and Kuhn have misled current theoretical investigations. Physicists have been too casual in dismissing the insights of successful established theories. Misled by Kuhn’s insistence on incommensurability across scientific revolutions, they fail to build on what we already know, which is how science has always moved forward.
Rovelli says his "own technical area", loop quantum gravity, does not make any sense, and he hopes philosophers will help make sense of it. No chance of that. Loop quantum gravity is a dead end. No good physics has come out of that field, and nothing ever will.

His article is really a defense of ancient philosophy. There is no example of any good from modern philosophers.


  1. Nice article, Roger! It really summarizes everything you argue for and have been doing so for years. Thanks for the enjoyable read...

  2. There are reputable philosophers that defend empiricism in much the same manner, such as Bas van Fraassen: "One of the reasons constructive empiricism is viewed as significant is that it carries on the tradition of the logical positivists without being saddled with the problematic aspects of the positivists’ positions. The constructive empiricist follows the logical positivists in rejecting metaphysical commitments in science, but she parts with them regarding their endorsement of the verificationist criterion of meaning, as well as their endorsement of the suggestion that theory-laden discourse can and should be removed from science. Before van Fraassen’s The Scientific Image, some philosophers had viewed scientific anti-realism as dead, because logical positivism was dead. Van Fraassen showed that there were other ways to be an empiricist with respect to science, without following in the footsteps of the logical positivists."

    The problem is that philosophy makes for more rather than less confusion, especially about simple things. The current post-post-post-modern gibberish proves that philosophy is an equally corrupt makework academic discipline removed from real problems. You are only inviting in even less practical people to meddle in science. One is bogged down in debates like the Duhem–Quine thesis.–Quine_thesis

    Pick theories we can understand, verify with experiments and use to make predictions. That's it. Philosophy is for morons.