2. Scientific progress as change-in-justification

Here is the justification account of scientific progress: science makes progress if and only if there is a change in justification. For now the formulation is incomplete because it is silent on what receives justification and what constitutes a change in justification—I address this in section 3. Here I defend the general plausibility of a justification account of scientific progress. Can an account of scientific progress have justification as its centerpiece?

Pretty much every philosopher writing about scientific progress seems to think that the answer is no. Rowbottom (Reference Rowbottom2008), for example, suggests that justification is only instrumental for scientific progress. Dellsén (Reference Dellsén2023) agrees. Though Bird (Reference Bird2008, 280) requires justification, he is explicit in his claim that nothing short of knowledge constitutes progress, and he specifically claims that justification, although necessary for knowledge and thus progress, is, without truth, insufficient for progress (see also Bird Reference Bird2007). I address this question more thoroughly in section 4, arguing that truth is not required for scientific progress. I note now only that much of science is epistemic in the truest sense of the word, namely, not about truth at all but about evidence and the evidence–hypothesis relation, trying to determine what hypotheses or theories are justified based on available evidence and to improve those justifications. Scientific practice justly just is about justification.

I address the sufficiency of justification (absent truth or knowledge) as constitutive of scientific progress in section 4. Dellsén (Reference Dellsén2016) argues against the necessity of justification for progress. His example is Einstein’s 1905 explanation of Brownian motion. Because on Dellsén’s noetic account of scientific progress, the ability of a theory to explain phenomena is a marker of progress, Einstein’s explanation of Brownian motion counted as progress. Yet, this explanation was based on the kinetic theory of heat, which at the time was speculative and so, claims Dellsén, unjustified. And thus, concludes Dellsén, justification is not necessary for scientific progress. However, precisely because the kinetic theory of heat was able to explain Brownian motion, the kinetic theory of heat received some degree of justification, because in general, the ability of a theory to explain a phenomenon provides some justification to that theory. So this is an example of progress, but contrary to Dellsén’s claim, this example involved justification.

Another argument Dellsén (Reference Dellsén2023) gives that strikes me as compelling involves imagining a scientific discipline with a track record of consistently generating false theories. That dismal track record gives scientists in that discipline reasons to think that any current theories are probably false, akin to the pessimistic meta-induction. Now suppose that the discipline develops strong evidence for a theory. This seems like progress, but, claims Dellsén, those scientists would be unjustified in believing that the theory is true (because of the dismal track record in that discipline), and thus, concludes Dellsén, the justification requirement for progress is too demanding. However, note that it is the requirement that beliefs in the truth of the theory be justified that is too demanding. This case involves a change in justification for the theory precisely because the case involves the acquisition of confirmatory evidence for the theory. There can be an increase in justification for some hypothesis without there being sufficient grounds to believe that hypothesis. So if one has the intuition that Dellsén does about this case, namely, that it involves progress, the change-in-justification account of progress accommodates that.

Refereeing the debate between the view that scientific progress is the accumulation of knowledge and the view that scientific progress is the accumulation of true scientific beliefs, Mizrahi and Buckwalter (Reference Mizrahi and Buckwalter2014) tested the intuitions of a large number of subjects and found that justification is important for intuitive judgments about what constitutes scientific progress. This provides some support for holding justification as a necessary component in an account of scientific progress.

An accumulation of new evidence can increase justification, and that would amount to scientific progress. The justification account of scientific progress is more general than the noetic, epistemic, and semantic accounts because it allows for nontheoretical progress. Dellsén (Reference Dellsén2018, 2), for example, claims that scientific progress is strictly about “improvement in our theories, hypotheses, or other representations of the world, rather than other improvements of or within science.” (So on Dellsén’s account, accumulation of more evidence would not count as progress, and nor would an increase in the confirmation of a hypothesis necessarily count as progress, because the mere increase in confirmation of a hypothesis does not need to involve an improvement of that hypothesis.) The noetic, epistemic, and semantic accounts of scientific progress are too theory-centric (for similar points, see Douglas Reference Douglas2014; Shan Reference Shan2019; Massimi Reference Massimi2022).

Shan (Reference Shan2019) recently updated the problem-solving account of scientific progress. In this insightful update, the articulation of scientific problems is deemed just as progressive as the proposal of solutions to those problems. I agree that articulation of problems is important. However, without a change in justification, neither the articulation of a scientific problem nor a proposed solution to a scientific problem should be seen as constituting scientific progress. The mere articulation of a scientific problem is like posing a rhetorical question without answering it. Having an articulated scientific problem can be important for the development of some research programs, though it is not necessary. Lucky discoveries can occur without articulated problems, as, for example, occurred with Fleming’s discovery of penicillin. That said, it is plausible to think that having articulated problems can contribute to scientific progress. (Bird and others rightly argue that contributing to progress does not necessarily constitute progress—just as a large grant for research may contribute to scientific progress but not constitute it.)

Justification according to what standard? One can perhaps simply adopt any favored account of justification on offer from epistemology. Yet I believe that two options are unattractive. One standard of justification could be strictly internalist by holding that beliefs are justified by the evidence immediately available to an individual scientist. This would be unsatisfying as an account of scientific progress, as it would render determinations of progress highly individualistic and idiosyncratic. Another standard could be that of an ideal epistemic community at the end of inquiry. That option would render justification epistemically inaccessible to virtually all practicing scientists, thereby sapping it of any practical, methodological bite for practicing scientists and of one of its advantages relative to a truth requirement for progress (section 4). An account of justification that sits somewhere between these two options is better. This could appeal to whatever principles and practices a scientific community establishes that serve to minimize epistemic risk, thereby enhancing the objectivity and reliability of its findings (Koskinen Reference Koskinen2020).

3. Change in what?

What changes in a change of justification? I describe three options. The first, based on the number of justified beliefs, is my least favorite. The second, based on a notion of graded justification, and the third, based on a notion of change in confirmation, are, to my mind, both plausible, and they are perhaps interchangeable. Because the formal apparatus of the third option is well developed, it allows me to explore a range of nuances, and thus my treatment of the third option is more extensive than the first two.

3.3 Change in confirmation

One way to explicate change-in-justification, taking its cue from recent work in formal epistemology, would be to understand a change in justification in terms of a change in confirmation.

The best-developed account of scientific confirmation is based on the tools of probability. Sprenger and Hartmann (Reference Sprenger and Hartmann2019) lay out the basics of Bayesian confirmation theory and then apply it to several topics in philosophy of science, including the tacking paradox, the grue paradox, and the paradox of the ravens. I extend this approach to give an account of scientific progress in which confirmation is central.

An obvious case of progress is when new evidence is generated that adds confirmation to a hypothesis. Yet both increases and decreases in confirmation can constitute scientific progress. A decrease in confirmation can occur in an instance of failed replication: scientists might have a relatively high degree of confirmation for some hypothesis because an initial experiment provided evidence supporting the hypothesis, yet if a subsequent experiment attempting to replicate that initial experiment provides evidence disconfirming that hypothesis, this can count as progress. Indeed, replication failures have become especially important recently due to the so-called replication crisis in psychology. For example, Baumeister et al. (Reference Baumeister, Bratslavsky, Muraven and Tice1998) published evidence supporting the existence of “ego depletion,” the putative phenomenon in which subjects’ self-control is a limited resource that can be used up; later, larger experiments did not observe ego depletion (e.g., Vohs et al. Reference Vohs, Schmeichel, Lohmann, Gronau, Finley, Ainsworth and Alquist2021), and such a replication failure should count as scientific progress.

When a scientist introduces a new hypothesis that can explain existing evidence better than already available hypotheses, that new hypothesis can undergo a huge increase in confirmation (from zero or undefined to substantial) while the already existing hypotheses undergo a decrease in confirmation (Lipton Reference Lipton2004). That is progress. A nice example of this was provided by Einstein, whose 1915 general theory of relativity was able to explain the precession of the perihelion of Mercury’s orbit, a by-then well-established empirical phenomenon that could not be explained by existing physical theory.

A distinction that goes back to Carnap is between absolute confirmation, the degree to which some hypothesis H is supported by evidence E, and incremental confirmation, the extent to which the support of H changes upon getting E. Absolute confirmation is represented by Bayesians as the posterior probability, or the probability of H given E, P(H|E). There are various measures of incremental confirmation, each with distinct formal representations. Two prominent measures include the difference measure, which is the difference between the posterior probability and the prior probability, P(H|E) − P(H), and the likelihood ratio measure, which is the ratio between the likelihood of E given H divided by the likelihood of E given a contrast hypothesis H′, P(E|H)/P(E|H′) (see Fitelson Reference Fitelson1999). Because progress implies change, one might think that the approach here is based on incremental confirmation, though a justified change in confirmation implies a change in absolute confirmation, so one can make sense of this account of scientific progress according to either absolute or incremental confirmation. As is standard, C(H,E) represents the incremental confirmation that E provides to H without specifying a particular confirmation measure, and C _i (H,E) represents the incremental confirmation that E provides to H by confirmation measure i.

For Bayesian accounts of confirmation like that of Sprenger and Hartmann (Reference Sprenger and Hartmann2019), probabilities are representations of an agent’s credence. To address the worry that such a subjective foundation cannot be the basis for characterizing central features of science, Sprenger and Hartmann respond by claiming that the agents they are modeling are ideal, rational, and responsive to evidence. Change in confirmation is represented using the formal measures noted earlier, and the probabilities represent credences of a rational scientist who responds appropriately to evidence such that their resulting credences are justified by their evidence.

Whether there is a unique way to appropriately respond to evidence is a controversial question in epistemology—for what it is worth, I do not believe that there is, yet arguing that point would take me astray (for differing views on the so-called uniqueness thesis, see White Reference White2005; Kelly Reference Kelly, Steup, Turri and Sosa2014). If there is a unique way to appropriately respond to evidence, then the formal measures of incremental confirmation are simply representations of that uniquely justified way to respond to evidence. If there is not a uniquely justified way to respond to evidence, then anyway, there are plausible constraints on justified responses to evidence.

Consider this example. Maria and Sasha want to evaluate hypothesis H, which says that “this drug does blah blah.” Both Maria and Sasha have the same prior, P(H). A randomized trial is performed that gives evidence (E) suggesting that the drug does blah blah. If uniqueness is true—if there is a unique way to appropriately respond to evidence—then when given E, both Maria and Sasha will assign the same degree of confirmation to H. If uniqueness is false, then their assessment of the confirmation provided to H could differ. Perhaps Maria thinks that randomized trials are not as epistemically important as they are often made out to be (having read Worrall Reference Worrall2002), whereas Sasha thinks that randomized trials are more reliable than the alternative (having read Larroulet Philippi Reference Larroulet Philippi2022). Yet for both Maria and Sasha, their posterior, P(H|E), must be greater than their prior, P(H), because E offers at least some confirmation of H (assuming the plausible “positive relevance” definition of evidence). Thus both Maria and Sasha conclude that H receives some incremental confirmation: for both Maria and Sasha, C(H,E) > 0. Thus, for both Maria and Sasha, according to the confirmation account of scientific progress, this episode involves scientific progress. (When given some other evidence E′, Maria and Sasha might disagree about which of E or E′ provides more confirmation to H and thus about which evidence contributes more scientific progress, but such disagreements are faithful to real scientific disputes.)

One challenge to this approach is that if both increases and decreases in confirmation can count as progress, then there can be a hypothesis that receives first an increase in confirmation and then a decrease of the same amount, and then an increase, and then a decrease, and so on, and that does not really look like progress. Consider confirmation of H by a sequence of experiments that generates E₁ − E _N accordingly, and we measure confirmation with the difference measure C _d . We can have

$$\eqalign{ & {{\rm{C}}_d}\left( {{\rm{H}},{{\rm{E}}_{\rm{1}}}} \right) = x \cr & {{\rm{C}}_d}\left( {{\rm{H}},{{\rm{E}}_{\rm{2}}}} \right) = - x \cr & {{\rm{C}}_d}\left( {{\rm{H}},{{\rm{E}}_{\rm{3}}}} \right) = x \cr & {{\rm{C}}_d}\left( {{\rm{H}},{{\rm{E}}_{\rm{4}}}} \right) = - x \cr} $$

and so on to N. At the end of this sequence, the posterior probability of the hypothesis would be the same as its prior was before the sequence of experiments began. It might seem unintuitive to count this as scientific progress. Yet it is consistent with the confirmation account of scientific progress.

If an episode in science went through a small number of such iterations, then I would have no problem calling that scientific progress. There are real cases that involve the plausibility of a hypothesis waxing and waning and then waxing again. For example, Margaret Mead (Reference Mead1928) shocked the world with her description of sexually permissive teenagers in Samoa; Derek Freeman (Reference Freeman1983) then argued that Mead’s evidence was unreliable, and thus the teenage sexual permissiveness hypothesis was disconfirmed; subsequently, Paul Shankman (Reference Shankman2009) argued that Freeman had exaggerated his criticisms of Mead, and thus the teenage sexual permissiveness hypothesis was plausible, which is roughly where things now stand.

However, I doubt that many real cases in science involve more than a handful of such iterations—I cannot think of any, though if that is just a result of my ignorance, then I await edification.

Another possible challenge to this approach would be any instance in which there is scientific progress with no change in confirmation. Yet I cannot think of any examples, and I am tempted to think that this is because of the analytic relationship between scientific progress and change in confirmation. Consider first an example in which one has a prior of zero for some hypothesis and acquires evidence about that hypothesis, none of which is confirmatory; there has been an accumulation of evidence but no change in confirmation. Is it progress? I do not think so. That is because hypotheses for which we have zero priors are like “Santa Claus exists” or “my body is composed of fewer than seven atoms.” Gathering evidence that provides no confirmation for such hypotheses is not scientific progress, and mutatis mutandis for priors of one (acquiring evidence that confirms the hypothesis “Santa Claus does not exist” is not scientifically progressive). If a posterior differs from the prior, and so there is a change in confirmation, there must be some newly developed confirmatory or disconfirmatory element, such as acquisition of evidence for the hypothesis or a refinement of the hypothesis, and such developments are progressive for science.

Evidence can, obviously, provide confirmation or disconfirmation to a hypothesis. One might be tempted to ask what the nature of evidence itself is. Addressing this question in any detail here would take this article astray. It is enough simply to say that evidence is that which provides confirmation or disconfirmation to hypotheses. The austere positive relevance definition of evidence holds that some evidence E is confirming evidence for a hypothesis H if and only if P(H|E) > P(H). For the present purpose of explicating scientific progress, that should be enough to say about evidence.

Nevertheless, consider Williamson’s (Reference Williamson2000) E = K thesis, which holds that one’s evidence is constituted by what one knows. On that account, gathering new evidence amounts to an accumulation of new knowledge, and if this is so, then one might think that the account of scientific progress based on a change in confirmation or justification by new evidence is, after all, a knowledge-based account; Bird (Reference Bird2022), for example, pursues such an approach to scientific progress. Yet we have already seen ways in which a change in justification can occur without gathering new evidence, such as by introducing new explanatory theories or refining existing theories, solidifying background assumptions, and appealing to theoretical features like simplicity or other nonevidential considerations, such as the no-alternatives argument. So even on such an account of evidence, a justification account of scientific progress does not reduce to a knowledge account.

I have defined scientific progress as a change in justification or confirmation. One might think that progress should be defined in terms of increase rather than mere change. That, however, would face the challenge mentioned earlier of explaining how a failed replication could count as progressive. More substantively, I believe that an account of scientific progress in terms of change in confirmation and an account in terms of increase in confirmation are equivalent. Suppose we are considering some hypothesis X and we get evidence E that provides some incremental disconfirmation to X; we can conceive an alternative hypothesis, Y, that says “not X,” and Y, then, gets an increase in confirmation due to E. There is a change in confirmation (specifically, a decrease in confirmation) of X but an increase in confirmation of Y. So increase-in-confirmation and change-in-confirmation are formally interchangeable as an account of scientific progress.

Some increments in confirmation may be minuscule. And sequences of increments in confirmation can involve diminishing returns. Suppose I want to know if a coin is biased to heads. I toss the coin. Heads. I toss again. Heads. I toss again. Tails. Ten tosses, eight heads. One hundred tosses, seventy-seven heads. One thousand tosses, 789 heads. So I am now thinking that this coin is biased roughly to 0.8 heads. The hypothesis “this coin is biased to 0.8 heads” received a lot of confirmation in the first ten tosses, but the amount of incremental confirmation received by the ten tosses between the 700th toss and the 710th toss is much, much less. I raise this point here because it will make sense of an important example in section 4.

4. Truth as convenient benediction

The justification account of scientific progress dispels with the necessity of accumulation of truths or related factive notions for scientific progress. Yet, a widespread belief is that the aim of science is truth or a related notion, such as knowledge. If the aim of science is truth or knowledge, then it is a natural thought that science makes progress as it accumulates truths or knowledge. We saw earlier that several prominent accounts of scientific progress have a truth requirement. My aim in this section is to offer three arguments against a truth requirement for scientific progress.

Ascriptions of scientific hypotheses as true are not typically part of routine scientific practice; rather, ascriptions of truth are typically retrospective benedictions. Such benedictions are convenient, as they provide a simple summary of the messy details of scientific work, for allocating credit, teaching students, distributing research funds, and communicating to the public. Truth is convenient benediction. This is not to say that truth is not important, or is not disquotational, or does not correspond; I believe that truth in general has those properties. My point is more modest—to call truth in science a benediction is to emphasize that ascertainment of truth can take a long time and, obviously and typically, occurs in retrospect.

In real time, scientists are able to ascertain justified changes in confirmation. In real time, scientists are not able to ascertain the achievement of truth. Benedictions of truth take time (Massimi Reference Massimi2016). When Watson and Crick finished building their model of the double helix structure of DNA, they were confident enough of their achievement to walk across the street to the Eagle pub in Cambridge to celebrate. They had a clear-eyed assessment of how well confirmed their model was. Yet their one-page 1953 paper in Nature was shot through with caution; they claimed that their model was a postulate, based on numerous assumptions, and that alternatives to their model, though unlikely, were possible. They were not giving their own finding a benediction. That benediction came nine years later, when they were awarded the Nobel Prize. So in some episodes of scientific progress, benedictions can be made soon after the scientific work itself. However, in other episodes of scientific progress, benedictions can take a very long time. For example, it took generations of scientists to properly establish Copernican theory (Westman Reference Westman2011).

Laudan (Reference Laudan1977) argued that real-time epistemic accessibility of scientific progress is a desideratum for an account of scientific progress—a scientist or a scientific community should be able to ascertain that by doing x, they are making progress. Just as a mountaineer should be able to determine if they are getting nearer to the summit, and just as a baker should be able to determine if the bread is rising, I find this epistemic accessibility requirement for scientific progress plausible. Laudan famously argued for antirealism (based on the pessimistic meta-induction); if antirealism is true, and if one held a truth requirement for scientific progress, then it would follow that science cannot make progress—Laudan took that as an argument against accounts of progress that have a truth requirement. Bird (Reference Bird2022) and others push back against Laudan by directly targeting the argument for antirealism. Yet one can adopt the epistemic accessibility desideratum without adopting antirealism. Here is the general point: the fact that it can take a long time after scientific work occurs for the truth of the findings of that work to receive benediction means that any account of scientific progress that maintains a truth requirement must violate the epistemic accessibility desideratum. (It also follows that truth cannot be a “norm of assertion” for science, contrary to Price’s [Reference Price2003] claim that truth is a norm for all assertoric discourse and to Bird’s [Reference Bird2022] claim that knowledge is a norm of correctness for science.)

Similarly, it can take a very long time to learn that one’s theories are false and not even approaching the truth. This raises the next problem for maintaining a truth requirement for scientific progress, what I call the Ptolemaic challenge. Ptolemaic astronomers toiled for centuries to tally the planets and stars and their positions over time. They developed an Earth-centered model of the solar system based on the geometry of epicycles (a smaller circle placed on the circumference of a larger circle). Their epicyclic models were very successful at explaining their observations, and when they observed anomalous celestial phenomena, they refined their models by adding more epicycles (For a detailed discussion of Ptolemaic astronomy, I recommend Kuhn’s 1957 book The Copernican Revolution). It was a research program that lasted for many centuries, based on rigorous observations that were accounted for by mathematical theorizing that became more and more sophisticated. Yet all those models were false, and they were not, over all those centuries, getting any closer to the truth, as they were all models of the solar system placing Earth at the center. To maintain a truth requirement for scientific progress requires one to hold that Ptolemaic astronomy made no progress. Not a drop.

I find it odd to think that Ptolemaic astronomy made no progress. More than odd. Such a view is offensive to those ancient late-night observers of the starry sky, those scientists of the oldest science, those curious heirs to Babylon and those diligent students of Aristotle, those scientists who spent centuries in the cold, dark nights of northern Africa to record the movements of stars and planets on clay tablets and who devised intricate theories based on models of epicycles on epicycles, those scientists whose forebears designed the pyramids of Egypt to align with the stars and who calculated Earth’s circumference to nearly its true value, those scientists who could at least offer a putative explanation of the westward motion of the sky and the eastward motion of the moon relative to the stars and the retrograde motion of planets by layering epicycles on epicycles, and who could predict astronomical observations to within the limits of what could be observed with the naked eye one thousand years into the future using epicycles on epicycles—epistemic feats surely more impressive than that which could be achieved today by most lovers of science.

Here we have the Ptolemaic challenge. If an account of scientific progress maintains a truth requirement, it must say that Ptolemaic astronomy made no progress. But Ptolemaic astronomy did make progress. The semantic, epistemic, and noetic accounts of scientific progress face the Ptolemaic challenge. For that reason, they are too demanding.

The Ptolemaic challenge also applies to the verisimilitude version of an epistemic account of scientific progress, as there is no sense in which subsequent iterations of Earth-centered models of the solar system were more truth-like. Niiniluoto (Reference Niiniluoto2014) distinguishes between real progress and estimated progress, where real progress is based on increasing verisimilitude and estimated progress is based on merely an apparent increase in verisimilitude. He would say that Ptolemaic astronomers merely seemed like they were making progress but that they were not in fact making progress. This, too, faces the Ptolemaic challenge.

One might think that after centuries of adding epicycles on epicycles, Ptolemaic astronomy was no longer making progress. Indeed, Lakatos’s (Reference Lakatos1978) attempt to articulate a demarcation criterion for scientific research programs had precisely this sort of concern in mind. Lakatos held that a research program, by which he meant the development and testing of a sequence of theories, is progressive if the sequence of theories makes more and more predictions and if more and more of those predictions turn out to be true; and if a research program is not progressive, then, Lakatos claimed, it is “degenerating.” On this account, later Ptolemaic astronomy was not progressive; it was degenerating. Yet, Lakatos’s demarcation criterion placed too much emphasis on novel predictions; philosophers of science have pretty much reached a consensus that while predicted evidence can be more confirming than merely accommodated evidence, that is not always the case, and accommodated evidence can provide some confirmation to a theory (though arguing this point would take me astray; see, e.g., Barnes Reference Barnes2008; Frisch Reference Frisch2015). Moreover, a research program can make little or no progress but need not be “degenerating.” Ptolemaic astronomy in the late Middle Ages was plausibly in a phase of “diminishing justificatory returns,” as mentioned in section 3—though some incremental confirmation could be gained by adding a 37th epicycle, it was very little.

Laudan (Reference Laudan1984) describes truth as a utopian aim for science, because, impressed by the pessimistic meta-induction, he claims that we can never achieve the aim, and even if we could, we could not know if the aim had been achieved. Bird (Reference Bird2022) rightly complains that this is an excessively skeptical position. With Bird, I agree that we can often come to know that science has achieved truth (though, as earlier, in science, that can take a long time). Yet sometimes we cannot know that we have achieved truth, or are approaching truth, and importantly, sometimes we cannot know that what we now take to be true is in fact false. That was the plight of the Ptolemaic astronomers for many centuries. Here my position is somewhere between Bird and Laudan. Truth is not a utopian norm, rather, it is a nirvana norm. With great diligence, some people may be able to achieve nirvana, just as with great diligence, science can achieve truth. Yet one might be approaching nirvana and not know it, and conversely, one might not be approaching nirvana but think otherwise.

Moreover, nirvana norms are not action guiding and can be used for assessment only retrospectively. Traffic laws guide action—they influence behavior in real time—and of course a police officer can appeal to a traffic law as the basis for pulling you over for speeding. A norm that says “seek truth” tells scientists little about how to behave, just as a norm that says “seek nirvana” tells me little about how to behave. Such abstract norms need supplementary, concrete, action-guiding norms. In Buddhism, action-guiding norms are articulated in the Noble Eightfold Path. Each path is constituted by concrete, action-guiding norms; the “right speech” path, for example, says: no lying, no rude speech, no idle chitchat; the “right livelihood” path says: do not earn money by selling weapons, living beings, meat, or alcohol. Telling a person to seek nirvana is to tell them nothing—it is a nirvana norm. Telling a person to follow the Noble Eightfold Path is to give them very concrete guidance on action. The equivalent concrete norms for science would be whatever principles and practices one has good reason to think minimize epistemic risks and thus are reliabilityenhancing and ground claims to justification (Koskinen Reference Koskinen2020).

I have given three arguments against maintaining a truth requirement for an account of scientific progress: the epistemic accessibility argument (truth as benediction), the Ptolemaic challenge, and the truth-is-a-nirvana-norm argument. To repeat, I am not suggesting that truth is unimportant or that science cannot attain truth. I am arguing only that scientific progress is to be judged by reference to changes in justification rather than achievement of truths or approximations to truth (which is, thus, a version of pragmatism, insofar as some pragmatists dispense with a truth norm but emphasize justification; see Rorty Reference Rorty1998). Science can come to discover truths about the world precisely by engaging in its justificatory practices, perhaps by adopting what Nagel (Reference Nagel1986) called a “view from nowhere.” However, science cannot adopt a view from no-who.

5. No view from no-who

Suppose Sasha is searching for the holy grail of science, the ultimate theory of everything, and after years of work, she makes a breakthrough discovery, a theory that unifies all physical laws and explains all existing anomalies. She writes up her finding. But she worries about her discovery being used to develop terrible weapons. She burns her manuscript, moves to Nepal and joins a Buddhist monastery, never speaks with anyone about her discovery, and lives out her final years in quiet solitude.

Sasha accumulated knowledge, a true finding that could solve many problems and that was, on traditional personalist grounds, justified. Some existing accounts of scientific progress would appear to maintain that Sasha made scientific progress. Yet she did not. I noted previously that scientific justification is communal and intersubjective. For a scientific achievement to contribute to scientific progress, there must be not only an in-principle possibility of community uptake but also some actual community uptake. Such uptake can take time, as occurred with the Copernican model of the solar system, but eventually, such uptake must occur. A finding that is observed by no one other than the scientist responsible for the finding can hardly be deemed scientific, let alone a contribution to scientific progress. Science cannot make progress with a view from no-who.

The cognitive achievements central to each of the accounts of scientific progress are nothing without community uptake. The existing literature on scientific progress has focused on these cognitive achievements, asking which kind of cognitive achievement is the fundamental kind for scientific progress. Yet Sasha’s story shows that this is incomplete.

As Merton (Reference Merton1942), Longino (Reference Longino1990), Massimi (Reference Massimi2022), and many others have emphasized, science is a social institution. Many scientists and philosophers of science have held that science is fundamentally public and that its methods and evidence must be intersubjectively accessible (e.g., Shapin and Schaffer Reference Shapin and Schaffer1985; Popper Reference Popper1959; though for pushback against this publicity requirement, see Goldman Reference Goldman1997). Moreover, some philosophers argue that scientific communities are themselves epistemic agents (e.g., Bird Reference Bird2022). A scientific finding must be made public in one way or another, at some time or other, for that finding to contribute to scientific progress, and the relevant scientific community must engage with that finding, and hold that finding to its standards, to determine if a change in confirmation pertaining to that finding is justified; if it is justified, the community can do further work on the hypothesis, refining it or relying on it to discover new findings; if it is not justified, further work can be done on it, or the finding can be discarded. (Ultimately, the community can decide whether the finding receives the benediction of truth, but as I argued in section 4, progress itself occurs at the moment of justified change in confirmation, not at the moment of benediction.)

Let us call this the community uptake requirement for scientific progress. One consideration in favor of the community uptake requirement is the simple fact that for future scientific work to develop based on an earlier finding, that finding must be available to other scientists. Another consideration in favor of the community uptake requirement is based on the lesson Longino (Reference Longino1990) taught us about the importance of criticism in science—if scientific findings are not shared in one way or another, they cannot be criticized, and criticism is a hallmark of objectivity. No one was able to critically evaluate Sasha’s discovery. Still another consideration in favor of the community uptake requirement is that science education requires the content of science to be available. Still another consideration in favor of the community uptake requirement is Bird’s (Reference Bird2022) argument that scientific communities themselves can be the bearers of scientific knowledge. Finally, benediction can occur only if the community uptake requirement is satisfied (For an extended and compelling argument that scientific justification is fundamentally communal and intersubjective, I recommend chapter 3 of Gerken [Reference Gerken2022] and chapter 4 of Bird [Reference Bird2022], the latter of which develops an account of “social knowing.”).

One might respond by holding that the work that goes into satisfying the community uptake requirement is not itself epistemic. This response could say that it is the cognitive achievement alone that matters for scientific progress. What is subsequently done with that cognitive achievement, goes this response, such as publication or discussion in the public sphere or education, does not add anything to the cognitive achievement itself. Many contingent, noncognitive (sociological) reasons could limit the uptake of scientific findings, but these should not speak against a scientific achievement counting as a contribution to progress. Yet this response is too insensitive to the social structure and function of science. (Making a related point, Harris [Reference Harris2021] argues to the effect that it is the doxastic states of communities of scientists rather than of individual scientists that matter for scientific progress.)

An interesting example of uptake not occurring can be seen in mathematics today in a dispute over whether the so-called abc conjecture has been proven. The abc conjecture is a fundamental conjecture in number theory, and were it true, many other famous theorems in number theory would follow, such as Fermat’s last theorem. In 2012 the mathematician Shinichi Mochizuki posted on his own website a putative proof of the abc conjecture that ran for six hundred pages and was based on novel mathematical theory that he alone had developed over years. Mochizuki told no colleagues about his proof, but he had little need to, as rumors were already circulating. Yet when fellow mathematicians began to discuss the preprint, they noted that “it involves ideas which are completely outside the mainstream” and that it was like a “paper from the future, or from outer space” (Ellenberg Reference Ellenberg2012). Most mathematicians today consider the conjecture still unproven, and some have noted specific flaws in the putative proof. Mochizuki claims that the failure is with other mathematicians and not the proof. I find it compelling to think that at this point, the Mochizuki proof has offered little progress; if, in the future, mathematicians come to accept the validity of the proof, then progress will be made, but importantly, the work that went into the proof itself will constitute only part of that progress.