[hist-analytic] Reichenbach, Carnap, Positivism

Baynesr at comcast.net Baynesr at comcast.net
Mon Sep 28 20:57:11 EDT 2009


Thanks for these very interesting remarks. It's nice to hear a new voice. Allow me just a few brief comments of a general or exegetical nature. Let's start with Part 1. You say, 

"While Reichenbach and Carnap are both interested in rational reconstruction of scientific theories, what this reconstruction consists of differs importantly between them. Reichenbach is much more interested in theory change," 

I don't see much textual evidence for Reichenbach having an interest in theory change, as such, except for considering the epistemological implications of moving from a Kantian to an Einsteinian view of space-time. Theory change, since Kuhn, has been quite the rage, but in Reichenbach's case I don't see it. I do, however, restrict myself to The Philosophy of Space and Time and The Theory of Relativity and A Priori Knowledge, and I think it's pretty clear that there is no discussion of this in his Experience and Prediction. You might be able to argue that there was an implicit historical agenda here, but that would require more evidence than has been forthcoming. So I'd have to see a couple of passages, preferably from one or more of these works to be convinced. 

Also, where do you see him make an effort to "show the development in terms of axiomatics," to take one example. On another matter, you remark, 

"analysis that differs from Kant in that the synthetic a priori propositions are constitutive, but not apodictic." 

Now I can find a lot of almost vicious comments on the synthetic apriori in his works, not to mention his letters to Russell housed at McMaster, so I have trouble figuring out how he might be regarded as offering synthetic a priori as "constitutive, but not apodictic." Now I think I understand why the "constitutive, but not apodictic" but in what way would he consider this "synthetic a priori "? Again, I've have to see some textual basis. I'm not that strongly opposed but it cuts against the grain of much of what I believe he has said etc. 

Part II 

I don't disagree with much here. For example, I think talk of truth as a throwback to Kant can be understood the way you have it. It requires a bit of finesse but I think it can be done as you say. 

Your remarks relating to Flavia Padovani are very interesting and well worth pursuing; give a bit of time to give this a look. 

Best wishes 


----- Original Message ----- 
From: "Steven Gimbel" <sgimbel at gettysburg.edu> 
To: "hist-analytic" <hist-analytic at simplelists.co.uk> 
Sent: Monday, September 28, 2009 2:40:01 PM GMT -05:00 US/Canada Eastern 
Subject: RE: Reichenbach, Carnap, Positivism 

“What motivated Reichenbach, and the Berlin positivists, was the idea that truth is not a very good concept for science to work with. Nothing is known with certainty to be true. What is known is what is probably true.” 

I think this is partially right, but there’s more to the story – more in two parts: 

Part I: 

While Reichenbach and Carnap are both interested in rational reconstruction of scientific theories, what this reconstruction consists of differs importantly between them.  Reichenbach is much more interested in theory change, in theories as part of an historical process, and wanting to show the development in terms of axiomatizations. 

I think the best way to interpret his first two books is attempts to model epistemological change on change in physical theory.  The move from Newtonian to Einsteinian mechanics not only presents us with an opportunity to rethink epistemic foundations, but also provides us with the template through which to understand not only this theory change, but the process in general.  Just as Newton’s results are first order approximations of Einstein’s, so too the concepts ought to be seen as “first order epistemic approximations.”  

In the place of Taylor series expansions, we put a sort of neo-Kantian analysis that differs from Kant in that the synthetic a priori propositions are constitutive, but not apodictic.  We need theory to make sense of the raw manifold of perception, but these theoretical postulates are revisable in light of observations. This is scientific progress – replacing one sets of axiomatic assertions with another whose empirical basis is more inclusive. 

When we do revise them, when we have a new theory take over for an old one, we start from the old concepts as our starting point, we cannot rebuild from pure observations in a protocol language.  As such, the new theory is still pregnant with the old to some degree.  In this way, the process is cumulative and progressive, but not completely revolutionary.  We know that the new theory’s axiom set with its basic concepts will also be replaced eventually. This, I believe, was one of Reichenbach’s motivations – he saw the error of Kant not only as tying his epistemology to Newtonian mechanics which was overthrown, but more generally tying it to any given theory.  He wanted to draw out the lessons of the rise of relativity theory without binding his view to the dictates of the theory in the same way.  Thus, talk of truth was a throwback to the Kantian apoctic claims – exactly what did in Kantianism in his view – and must be avoided.  Rather, scientific theories in the move from Newton to Einstein are getting better, and hence we need to speak in terms of degrees, shades.  This requires abandoning talk of truth for talk of probabilities. 

Part II: 

Here, I’m pulling from the wonderful work of Flavia Padovani, whose scholarship on probability and causality in Reichenbach’s early writings is well worth the time.  

Reichenbach’s pre-relativity work (especially his dissertation of 1915) focuses on the relationship between probability and physics.  He was an engineer before turning philosopher and so he appreciated the pragmatic as much as the theoretical.  As such, the advances in statistical mechanics fascinated him.  Here the theoretical instrument of statistics turned into the generator of actual physical laws.  That’s weird and seemed to indicate something deeper.  

Independent of statistical mechanics, though, the same lack of absolute determination was at play in anything that required measurement, and all scientific theories begin with measurement.  There is therefore a probabilistic element underlying all scientific investigation.  How to relate the principles of probability and the principle of causality within an intellectual framework that supports laws of nature became the central question of epistemology for him.  As such, the move away from truth to something necessary. 

If you combine his early interest in the role of probability with his interest in concept change from Einstein’s seminar at Berlin, the rejection of truth talk for probability talk seems quite natural.  Well, to some degree… 


Steve Gimbel 

Chair, Department of Philosophy 

Gettysburg College 

blog: Philosophers' Playground 

From: hist-analytic-manager at simplelists.com [mailto:hist-analytic-manager at simplelists.com] On Behalf Of Baynesr at comcast.net 
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