7

Can someone name the most well known philosophers to explicitly put forward an idea along the lines that formal systems can only be used descriptively, not prescriptively - that they're just a model, and when they disagree with us, it is them that is wrong - that human judgement trumps logic.

I ask because it feels like it's an idea that would have some history to it.

  • Hume: related? – user3164 Mar 29 '14 at 7:05
  • Willard van Orman Quine states a philosophy that consider all science as a big structure with external layers more strictly connected to the experience and innner layers more "protected", but all layers are, in principle, revisable according to the "clash" with reality. The "most inner" layer is logic, but it is still not unavoidable. – Mauro ALLEGRANZA Mar 29 '14 at 7:22
  • @GlenTheUdderboat close, doesn't quite hit the nail on the head. – Lucas Mar 29 '14 at 15:46
  • @MauroALLEGRANZA That seems to fit quite nicely. Quite modern (by philosophical standards) - I wonder if there is anything older. – Lucas Mar 29 '14 at 15:50
  • You may have to be more specific. Logic is a form of human judgement. "When human judgement trumps logic", which other forms of human judgement, with what foundations, are you speaking of? Depending on your answer, Sir Francis Bacon (with his criticism of scholastic thought) may be a candidate answer, if you allow "comparison experience", albeit supplemented by logic, as a form of human judgement. – Niel de Beaudrap Mar 30 '14 at 10:14
2

Hilary Putnam argues that formal systems cannot even be used to perform hypothesis selection. Whether you wish to characterize this as "prescription" is up to you, but one might suspect that if formal systems cannot serve here exclusively, they also cannot serve exclusively in other domains with a prescriptive element (e.g. ethics).

Epistemic Values are Values Too
The classical pragmatists, Peirce, James, Dewey, and Mead, all held that value and normativity permeate all of experience. In the philosophy of science, what this point of view implied is that normative judgments are essential to the practice of science itself. These pragmatist philosophers did not refer only to the kind of normative judgments that we call "moral" or "ethical"; judgments of "coherence," "plausibility," "reasonableness," "simplicity," and of what Dirac famously called the beauty of a hypothesis, are all normative judgments in Charles Peirce's sense, judgments of "what ought to be" in the case of reasoning.[7]
    Carnap tried to avoid admitting this by seeking to reduce hypothesis-selection to an algorithm—a project to which he devoted most of his energies beginning in the early 1950s, but without success. In Chapter 7, I shall look in detail at this and other unsuccessful attempts by various logical positivists (as well as Karl Popper) to avoid conceding that theory selection always presupposes values, and we shall see that they were, one and all, failures. But just as these empiricist philosophers were determined to shut their eyes to the fact that judgment of coherence, simplicity (which is itself a whole bundle of different values, not just one "parameter"), beauty, naturalness, and so on, are presupposed by physical science, likewise many today who refer to values as purely "subjective" and science as purely "objective" continue to shut their eyes to this same fact. Yet coherence and simplicity and the like are values. (The Collapse of the Fact/Value Dichotomy, 30–31)

When Carnap failed to find "an algorithm", he failed to find a formal system. When Putnam talks about "values", he means areas of human judgment which cannot be encapsulated in formal systems.

This being said, it's not clear that the right thing to say is "human judgement trumps logic". There are many kinds of logic. Instead, what I think you really want to say is that humans can always find a given formal system to be too restrictive for current circumstances, and thus "grow" it in order to handle the new situation. One might view this as "rationalizing", but that would presume that our minds cannot grasp on to higher orders of logic than they can formalize. This seems contentious, given concepts such as tacit knowledge and the more general unarticulated background. Any stance of scientific realism must suppose that the new rationality of a scientific revolution somehow continues the old understanding; otherwise, you end up calling it completely wrong. There is, however, also a discontinuity in scientific revolutions, with many treatments. One of my favorites is Alasdair MacIntyre's 1977 Epistemological Crises, Dramatic Narrative and the Philosophy Of Science, in The Monist.

3

It is reasonable to mention Wittgenstein in this connection. Brouwer is also relevant as he saw logic as secondary to mathematics. In Brouwers case it is rather clear-cut that he rejected logic as a norm. For him mathematics was an activity in the mind of the mathematician and this determines what can and cannot not be done. The mathematical activity is thus prior to any language that can communicate the constructions. I hesitate to say anything about Wittgenstein in this connection because it is hard not to misrepresent what he said. I remember seeing somewhere that Russell had to write an evaluation of Wittgenstein's work around 1929-30 in order for W. to get some stipend or something. Russell wrote that W. work was very interesting but that he (Russell) hoped that it would not be true because if it were things would get very complicated in philosophy. If Tractatus was a sort of early culmination of using logic in philosophy then W. later work attempted to show how very limited this approach was.

  • In Brouwers case it is rather clear-cut that he rejected logic as a norm. For him mathematics was an activity in the mind of the mathematician and this determines what can and cannot not be done. The mathematical activity is thus prior to any language that can communicate the constructions. – Anders Göransson Nov 15 '16 at 12:15
  • I hesitate to say anything about Wittgenstein in this connection because it is hard not to misrepresent what he said. I remember seeing somewhere that Russell had to wright an evaluation of Wittgenstein's work around 1929-30 in order for W. to get some stipend or something. Russell wrote that W. work was very interesting but that he (Russell) hoped that it would not be true because if it were things would get very complicated in philosophy. – Anders Göransson Nov 15 '16 at 12:28
  • @virmaior thank you for pointing this out. Can I remove the comments? – Anders Göransson Nov 15 '16 at 12:50
  • Yes, there should be an X you can do next your own comments. – virmaior Nov 15 '16 at 12:52
  • @virmaior Thank you. I might miss something but I cannot find any "delete" or "X" or some such thing next to the comments. Maybe I am underpriviliged enough to not be allow to delete my own comments? – Anders Göransson Nov 15 '16 at 12:57
2

For your question I would recommend the preface of Henri Poincaré's Science and Hypothesis (1905), particularly this piece:

For [in mathematics] the mind may affirm because it lays down its own laws; but let us clearly understand that while these laws are imposed on our science, which otherwise could not exist, they are not imposed on Nature. Are they then arbitrary? No; for if they were, they would not be fertile. Experience leaves us our freedom of choice, but it guides us by helping us to discern the most convenient path to follow. Our laws are therefore like those of an absolute monarch, who is wise and consults his council of state.

You can also see Feynman's introductory lectures, particularly this excerpt on the Nature of Scientific Thinking (1961).

0

Three nice answers and not a single upvote, I certainly won't put much effort into my answer under these circumstances.

Frank P. Ramsey in

"Truth and Probability" written 1926. Published 1931 in Foundations of Mathematics and other Logical Essays, Ch. VII, p.156-198. Edited by R.B. Braithwaite. London: Kegan, Paul, Trench, Trubner & Co. Ltd. New York: Harcourt, Brace and Company

Ramsey’s paper has 5 sections:

(1) The Frequency Theory
(2) Mr Keynes’ Theory
(3) Degrees of Belief
(4) The Logic of Consistency
(5) The Logic of Truth

The last section of Ramsey's paper is called "(5) The Logic of Truth". It contrasts with the precious section called "(4) The Logic of Consistency". He stresses that making predictions close to the truth is totally different from making consistent predictions. He stresses specifically that "induction" belongs to "The Logic of Truth", and has nothing to do with "The Logic of Consistency".

  • I kind of stopped paying attention to Phil.SE. ages ago. I'll make an effort to check over the answers and accept one. – Lucas Nov 18 '16 at 10:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.