- Email: [email protected]
N-rays and the semantic view of scientific progress
Stud. Hist. Phil. Sci. 39 (2008) 277–278
Contents lists available at ScienceDirect
Stud. Hist. Phil. Sci. journal homepage: www.elsevier.com/locate/shpsa
Discussion
N-rays and the semantic view of scientific progress Darrell P. Rowbottom School of Physics, University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, UK; Department of Philosophy, University of Bristol, 9 Woodland Road, Bristol BS8 1TB, UK
a r t i c l e Keywords: Scientific progress Goal of inquiry Value problem Alexander Bird
i n f o
a b s t r a c t This paper challenges a recent argument of Bird’s, which involves imagining that Réné Blondlot’s belief in N-rays was true, in favour of the view that scientific progress should be understood in terms of knowledge rather than truth. By considering several variants of Bird’s thought-experiment, it shows that the semantic account of progress cannot be so easily vanquished. A key possibility is that justification is only instrumental in, and not partly constitutive of, progress. Ó 2008 Elsevier Ltd. All rights reserved.
When citing this paper, please use the full journal title Studies in History and Philosophy of Science
In the course of arguing that an epistemic view of scientific progress is preferable to a semantic view—i.e. that scientific progress should be understood in terms of knowledge rather than truth—Bird (2007, p. 67) suggests the following thought-experiment: Réné Blondlot believed in the existence of what he called N-rays for what it is clear were entirely spurious and irrational reasons. Imagine for sake of argument that we were to discover that there are in fact hitherto unobserved entities answering to Blondlot’s description of N-rays. So Blondlot’s belief in N-rays would have been true but unjustified and not knowledge. The semantic approach would have to regard Blondlot’s belief (which was widely shared in France) as constituting progress. That is clearly wrong. Even if that is wrong, however, it is far from clear that this is an argument against the semantic approach. First, Blondlot’s belief in N-rays was due, in part if not in whole, to several of his other false beliefs.1 So even if ‘N-rays exist’ is true, an advocate of the semantic view of progress need not accept that Blondlot’s beliefs about N-rays, taken as a whole, were progressive. (Bird does not say otherwise, but the worry is that our intuitions concerning the thought-experiment are heavily dependent on this consideration.) Second, note that we
must not confuse an individual scientist’s beliefs with those accepted by the scientific community. An advocate of the semantic view need not accept that Blondlot’s beliefs about N-rays were relevant at all—any more, that is, than are those of some contemporary scientists about God. Instead, we may have to consider only those theories (or theoretical entities) which are assented to by the majority of professional scientists, are discussed in textbooks and university lectures, and so on. (Something like the ‘objective knowledge’ of Popper (1972) may be relevant here.2) Third and finally, it is important to consider degrees of belief rather than ‘on–off’ beliefs. To have had a degree of belief in ‘N-rays exist’ of 0.55, as a French scientist vaguely acquainted with Blondlot’s work, might not have been unreasonable.3 But this might count as believing the relevant proposition, in common parlance. In light of these considerations, Bird’s thought-experiment might be altered as follows. Imagine not only that N-rays exist, but also that most of the scientific community, including Blondlot, were brainwashed and hypnotised overnight so that they were (A) highly convinced that N-rays exist, but also (B) highly convinced that there was no evidence for the existence of N-rays. Imagine further that key texts were rewritten such that they described N-rays and their effects, but referred to no experimental evidence—papers,
E-mail address: [email protected] See, for instance, the accounts of Lagemann (1977) and Nye (1980). 2 The quotations which Bird (2007), n. 1, uses from Bacon and Bragg both support this view; Bacon says ‘many will go about’, and Bragg refers to ‘our knowledge’. In addition, Feyerabend (1981) suggests that Aristotle shared a similar view. 3 More generally, rationality of belief cannot be determined without appeal to considerations involving degree. ‘I believe that p’ and ‘I do not believe that not-p’ can both hold when my degrees of belief that p and not-p do not sum to unity. 1
0039-3681/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.shpsa.2008.03.010
278
D.P. Rowbottom / Stud. Hist. Phil. Sci. 39 (2008) 277–278
etc.—in support of their existence. (If desired, also suppose that the brainwashers and rewriters had no beliefs and/or evidence that N-rays exist.) Would this have constituted progress? Here is a plausible account of what would have happened next. The scientists would have woken up with a strong conviction that N-rays exist, but not been able to remember who discovered them, or recall any circumstance in which they were experimentally isolated. Several of those scientists would have been puzzled, and consequently have consulted their colleagues and texts. They would have discovered that there was widespread consensus. They might even have discovered inconsistencies, for example that some authors who had apparently written about N-rays didn’t remember doing so! But they would not have discovered any (honest) reports concerning experiments involving N-rays. So what would they have done? They would have looked for N-rays. It is plausible that this would have been progressive in some sense. The advocate of the epistemic view of progress, such as Bird, might respond with a two-pronged counterattack. First, isn’t it possible, equally, for false beliefs to act as effective motivators? And likewise, isn’t it true that false assumptions can be central to highly progressive research programmes? Second, wouldn’t the conviction that N-rays exist only have been responsible for progress—and not constituted progress—in the modified thoughtexperiment? Both of these points are legitimate, but they do not settle the matter. In order to see this, consider one final alteration to the thought-experiment. Imagine that the brainwashers and rewriters also provided the scientific community with ample false evidence that N-rays exist: reports and memories of experiments which never happened (but which might have resulted in the observation of N-rays if they had been performed, in some cases), a fictional tale about how they were discovered, and so forth. Now ‘N-rays exist’ would have been known to the community, according to a simple JTB account of knowledge. (Note also that this may be the case under an externalist account of justification. A ‘reliable method’, for example consulting papers and memories, may sometimes lead to false beliefs.4) But isn’t it plausible that the community would have been in a worse situation than that described previously? And wouldn’t this have been due to all the false beliefs they had gained? So the defender of the semantic view of progress might suggest. Admittedly, Bird (2007, p. 71) doesn’t claim that justification and truth are sufficient for progress; instead, he claims only that both are necessary. But the final version of the N-ray thoughtexperiment, above, suggests that justification for the relevant true belief can be undesirable.5 Wouldn’t we be better off having an unjustified true belief that ‘N-rays exist’ and being neutral concerning whether there is any evidence to that effect rather than having a justified true belief that ‘N-rays exist’ based on justified false beliefs in a great deal of evidence to that effect? Bird might reply that this problem can be solved by stipulating that the knowledge that ‘N-rays exist’ must be based on evidence which is known; that we must know ‘all the way down’. Yet the advocate of the semantic view
4
could equally say that the true belief that ‘N-rays exist’ should be based on evidence which is true.6 Ultimately, these considerations appear to indicate the significance of what is known as ‘the value problem’ in epistemology, as discussed by Jones (1997): why and when, if at all, is knowledge more valuable than true belief?7 Furthermore, it would seem that we need to consider what, precisely, our cognitive goals are (and/ or should be). According to a popular view in contemporary epistemology, justification is only interesting in so far as truth is the main aim; but this suggests that justification is only instrumental in (and not partially constitutive of) progress.8 This is nicely summarized by BonJour (1985, pp. 7–8): Why should we . . . care whether our beliefs are epistemically justified? . . . the goal of our distinctively cognitive endeavors is truth . . . if finding epistemically justified beliefs did not substantially increase the likelihood of finding true ones, then epistemic justification would be irrelevant to our main cognitive goal and of dubious worth . . . Epistemic justification is therefore in the final analysis only an instrumental value, not an intrinsic one. Acknowledgements My work on this paper was supported by the John Templeton Foundation, as part of the project ‘Why ‘‘Why?”—Methodological and Philosophical Issues at the Physics–Biology Interface’. References Bird, A. (2007). What is scientific progress? Noûs, 41, 64–89. BonJour, L. (1985). The structure of empirical knowledge. Cambridge, MA: Harvard University Press. Clark, M. (1963). Knowledge and grounds: A comment on Mr. Gettier’s paper. Analysis, 24, 46–48. Conee, E. (2004). The truth connection. In E. Conee & R. Feldman, Evidentialism: Essays in epistemology (pp. 242–259). Oxford: Oxford University Press. David, M. (2001). Truth as the epistemic goal. In M. Steup (Ed.), Knowledge, truth, and duty: Essays on epistemic justification, responsibility, and virtue (pp. 151–169). Oxford: Oxford University Press. David, M. (2005). Truth as the primary epistemic goal: A working hypothesis. In M. Steup & E. Sosa (Eds.), Contemporary debates in epistemology (pp. 296–312). Oxford: Blackwell. Feyerabend, P. K. (1981). Popper’s Objective knowledge. In P. K. Feyerabend, Philosophical papers, Vol. 2. Problems of empiricism (pp. 168–201). Cambridge: Cambridge University Press. Jones, W. (1997). Why do we value knowledge? American Philosophical Quarterly, 34, 423–439. Kvanvig, J. (2005). Truth is not the primary epistemic goal. In M. Steup & E. Sosa (Eds.), Contemporary debates in epistemology (pp. 285–295). Oxford: Blackwell. Lagemann, R. T. (1977). New light on old rays: N rays. American Journal of Physics, 45, 281–284. Nye, M. J. (1980). N-rays: An episode in the history and psychology of science. Historical Studies in the Physical Sciences, 11, 125–156. Popper, K. R. (1972). Objective knowledge. Oxford: Oxford University Press. Sartwell, C. (1992). Why knowledge is merely true belief. Journal of Philosophy, 89, 167–180.
Bird (2007), p. 71, does not make it clear what he means by ‘reliable’—an all-too-common problem, alas—but presumably he does not mean ‘error-free’. This holds even if ‘N-rays exist’ is not known, because of the Gettier problem. 6 Similarly, Clark (1963, p. 46) suggests that S can know that p only if ‘it is on true grounds that S believes that p’. The stipulation is not ‘it is on justified true grounds that S believes that p’. 7 That is, provided we work on the assumption that Sartwell (1992) is incorrect that knowledge is identical to true belief. 8 See also Kvanvig (2005), David (2005), Conee (2004), and David (2001). 5
Contents lists available at ScienceDirect
Stud. Hist. Phil. Sci. journal homepage: www.elsevier.com/locate/shpsa
Discussion
N-rays and the semantic view of scientific progress Darrell P. Rowbottom School of Physics, University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, UK; Department of Philosophy, University of Bristol, 9 Woodland Road, Bristol BS8 1TB, UK
a r t i c l e Keywords: Scientific progress Goal of inquiry Value problem Alexander Bird
i n f o
a b s t r a c t This paper challenges a recent argument of Bird’s, which involves imagining that Réné Blondlot’s belief in N-rays was true, in favour of the view that scientific progress should be understood in terms of knowledge rather than truth. By considering several variants of Bird’s thought-experiment, it shows that the semantic account of progress cannot be so easily vanquished. A key possibility is that justification is only instrumental in, and not partly constitutive of, progress. Ó 2008 Elsevier Ltd. All rights reserved.
When citing this paper, please use the full journal title Studies in History and Philosophy of Science
In the course of arguing that an epistemic view of scientific progress is preferable to a semantic view—i.e. that scientific progress should be understood in terms of knowledge rather than truth—Bird (2007, p. 67) suggests the following thought-experiment: Réné Blondlot believed in the existence of what he called N-rays for what it is clear were entirely spurious and irrational reasons. Imagine for sake of argument that we were to discover that there are in fact hitherto unobserved entities answering to Blondlot’s description of N-rays. So Blondlot’s belief in N-rays would have been true but unjustified and not knowledge. The semantic approach would have to regard Blondlot’s belief (which was widely shared in France) as constituting progress. That is clearly wrong. Even if that is wrong, however, it is far from clear that this is an argument against the semantic approach. First, Blondlot’s belief in N-rays was due, in part if not in whole, to several of his other false beliefs.1 So even if ‘N-rays exist’ is true, an advocate of the semantic view of progress need not accept that Blondlot’s beliefs about N-rays, taken as a whole, were progressive. (Bird does not say otherwise, but the worry is that our intuitions concerning the thought-experiment are heavily dependent on this consideration.) Second, note that we
must not confuse an individual scientist’s beliefs with those accepted by the scientific community. An advocate of the semantic view need not accept that Blondlot’s beliefs about N-rays were relevant at all—any more, that is, than are those of some contemporary scientists about God. Instead, we may have to consider only those theories (or theoretical entities) which are assented to by the majority of professional scientists, are discussed in textbooks and university lectures, and so on. (Something like the ‘objective knowledge’ of Popper (1972) may be relevant here.2) Third and finally, it is important to consider degrees of belief rather than ‘on–off’ beliefs. To have had a degree of belief in ‘N-rays exist’ of 0.55, as a French scientist vaguely acquainted with Blondlot’s work, might not have been unreasonable.3 But this might count as believing the relevant proposition, in common parlance. In light of these considerations, Bird’s thought-experiment might be altered as follows. Imagine not only that N-rays exist, but also that most of the scientific community, including Blondlot, were brainwashed and hypnotised overnight so that they were (A) highly convinced that N-rays exist, but also (B) highly convinced that there was no evidence for the existence of N-rays. Imagine further that key texts were rewritten such that they described N-rays and their effects, but referred to no experimental evidence—papers,
E-mail address: [email protected] See, for instance, the accounts of Lagemann (1977) and Nye (1980). 2 The quotations which Bird (2007), n. 1, uses from Bacon and Bragg both support this view; Bacon says ‘many will go about’, and Bragg refers to ‘our knowledge’. In addition, Feyerabend (1981) suggests that Aristotle shared a similar view. 3 More generally, rationality of belief cannot be determined without appeal to considerations involving degree. ‘I believe that p’ and ‘I do not believe that not-p’ can both hold when my degrees of belief that p and not-p do not sum to unity. 1
0039-3681/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.shpsa.2008.03.010
278
D.P. Rowbottom / Stud. Hist. Phil. Sci. 39 (2008) 277–278
etc.—in support of their existence. (If desired, also suppose that the brainwashers and rewriters had no beliefs and/or evidence that N-rays exist.) Would this have constituted progress? Here is a plausible account of what would have happened next. The scientists would have woken up with a strong conviction that N-rays exist, but not been able to remember who discovered them, or recall any circumstance in which they were experimentally isolated. Several of those scientists would have been puzzled, and consequently have consulted their colleagues and texts. They would have discovered that there was widespread consensus. They might even have discovered inconsistencies, for example that some authors who had apparently written about N-rays didn’t remember doing so! But they would not have discovered any (honest) reports concerning experiments involving N-rays. So what would they have done? They would have looked for N-rays. It is plausible that this would have been progressive in some sense. The advocate of the epistemic view of progress, such as Bird, might respond with a two-pronged counterattack. First, isn’t it possible, equally, for false beliefs to act as effective motivators? And likewise, isn’t it true that false assumptions can be central to highly progressive research programmes? Second, wouldn’t the conviction that N-rays exist only have been responsible for progress—and not constituted progress—in the modified thoughtexperiment? Both of these points are legitimate, but they do not settle the matter. In order to see this, consider one final alteration to the thought-experiment. Imagine that the brainwashers and rewriters also provided the scientific community with ample false evidence that N-rays exist: reports and memories of experiments which never happened (but which might have resulted in the observation of N-rays if they had been performed, in some cases), a fictional tale about how they were discovered, and so forth. Now ‘N-rays exist’ would have been known to the community, according to a simple JTB account of knowledge. (Note also that this may be the case under an externalist account of justification. A ‘reliable method’, for example consulting papers and memories, may sometimes lead to false beliefs.4) But isn’t it plausible that the community would have been in a worse situation than that described previously? And wouldn’t this have been due to all the false beliefs they had gained? So the defender of the semantic view of progress might suggest. Admittedly, Bird (2007, p. 71) doesn’t claim that justification and truth are sufficient for progress; instead, he claims only that both are necessary. But the final version of the N-ray thoughtexperiment, above, suggests that justification for the relevant true belief can be undesirable.5 Wouldn’t we be better off having an unjustified true belief that ‘N-rays exist’ and being neutral concerning whether there is any evidence to that effect rather than having a justified true belief that ‘N-rays exist’ based on justified false beliefs in a great deal of evidence to that effect? Bird might reply that this problem can be solved by stipulating that the knowledge that ‘N-rays exist’ must be based on evidence which is known; that we must know ‘all the way down’. Yet the advocate of the semantic view
4
could equally say that the true belief that ‘N-rays exist’ should be based on evidence which is true.6 Ultimately, these considerations appear to indicate the significance of what is known as ‘the value problem’ in epistemology, as discussed by Jones (1997): why and when, if at all, is knowledge more valuable than true belief?7 Furthermore, it would seem that we need to consider what, precisely, our cognitive goals are (and/ or should be). According to a popular view in contemporary epistemology, justification is only interesting in so far as truth is the main aim; but this suggests that justification is only instrumental in (and not partially constitutive of) progress.8 This is nicely summarized by BonJour (1985, pp. 7–8): Why should we . . . care whether our beliefs are epistemically justified? . . . the goal of our distinctively cognitive endeavors is truth . . . if finding epistemically justified beliefs did not substantially increase the likelihood of finding true ones, then epistemic justification would be irrelevant to our main cognitive goal and of dubious worth . . . Epistemic justification is therefore in the final analysis only an instrumental value, not an intrinsic one. Acknowledgements My work on this paper was supported by the John Templeton Foundation, as part of the project ‘Why ‘‘Why?”—Methodological and Philosophical Issues at the Physics–Biology Interface’. References Bird, A. (2007). What is scientific progress? Noûs, 41, 64–89. BonJour, L. (1985). The structure of empirical knowledge. Cambridge, MA: Harvard University Press. Clark, M. (1963). Knowledge and grounds: A comment on Mr. Gettier’s paper. Analysis, 24, 46–48. Conee, E. (2004). The truth connection. In E. Conee & R. Feldman, Evidentialism: Essays in epistemology (pp. 242–259). Oxford: Oxford University Press. David, M. (2001). Truth as the epistemic goal. In M. Steup (Ed.), Knowledge, truth, and duty: Essays on epistemic justification, responsibility, and virtue (pp. 151–169). Oxford: Oxford University Press. David, M. (2005). Truth as the primary epistemic goal: A working hypothesis. In M. Steup & E. Sosa (Eds.), Contemporary debates in epistemology (pp. 296–312). Oxford: Blackwell. Feyerabend, P. K. (1981). Popper’s Objective knowledge. In P. K. Feyerabend, Philosophical papers, Vol. 2. Problems of empiricism (pp. 168–201). Cambridge: Cambridge University Press. Jones, W. (1997). Why do we value knowledge? American Philosophical Quarterly, 34, 423–439. Kvanvig, J. (2005). Truth is not the primary epistemic goal. In M. Steup & E. Sosa (Eds.), Contemporary debates in epistemology (pp. 285–295). Oxford: Blackwell. Lagemann, R. T. (1977). New light on old rays: N rays. American Journal of Physics, 45, 281–284. Nye, M. J. (1980). N-rays: An episode in the history and psychology of science. Historical Studies in the Physical Sciences, 11, 125–156. Popper, K. R. (1972). Objective knowledge. Oxford: Oxford University Press. Sartwell, C. (1992). Why knowledge is merely true belief. Journal of Philosophy, 89, 167–180.
Bird (2007), p. 71, does not make it clear what he means by ‘reliable’—an all-too-common problem, alas—but presumably he does not mean ‘error-free’. This holds even if ‘N-rays exist’ is not known, because of the Gettier problem. 6 Similarly, Clark (1963, p. 46) suggests that S can know that p only if ‘it is on true grounds that S believes that p’. The stipulation is not ‘it is on justified true grounds that S believes that p’. 7 That is, provided we work on the assumption that Sartwell (1992) is incorrect that knowledge is identical to true belief. 8 See also Kvanvig (2005), David (2005), Conee (2004), and David (2001). 5