This is a follow up to Rafe’s post The Stanford Encyclopedia of Philosophy vs Karl Popper in which I reply to the Encyclopedia’s criticism of Popper’s position. The major defect of these criticisms is that they don’t seem to take account of the fact that Popper thought all knowledge was conjectural, and that this was his position since he first wrote Logic of Scientific Discovery.
I will take criticisms 1 and 3 first because they are similar in character. First, criticism 1:
[Popper] asserts that basic statements themselves are open-ended hypotheses: they have a certain causal relationship with experience, but they are not determined by experience, and they cannot be verified or confirmed by experience. However, this poses a difficulty regarding the consistency of Popper’s theory: if a theory X is to be genuinely testable (and so scientific) it must be possible to determine whether or not the basic propositions which would, if true, falsify it, are actually true or false (i.e., whether its potential falsifiers are actual falsifiers). But how can this be known, if such basic statements cannot be verified by experience? Popper’s answer is that ‘basic statements are not justifiable by our immediate experiences, but are … accepted by an act, a free decision’. (Logic of Scientific Discovery, 109). However, and notwithstanding Popper’s claims to the contrary, this itself seems to be a refined form of conventionalism—it implies that it is almost entirely an arbitrary matter whether it is accepted that a potential falsifier is an actual one, and consequently that the falsification of a theory is itself the function of a ‘free’ and arbitrary act.
I think we have to be a bit suspicious here when the author of this article states that Popper’s position is a ‘refined’ form of conventionalism: what refinement is he talking about and does it make a difference? In fact, the refinement makes a very large difference.
Before I answer criticism 1 I will quote criticism 3 because the answers to these two criticisms are related. Criticism 3:
Popper’s final position is that he acknowledges that it is impossible to discriminate science from non-science on the basis of the falsifiability of the scientific statements alone; he recognizes that scientific theories are predictive, and consequently prohibitive, only when taken in conjunction with auxiliary hypotheses, and he also recognizes that readjustment or modification of the latter is an integral part of scientific practice. Hence his final concern is to outline conditions which indicate when such modification is genuinely scientific, and when it is merely ad hoc. This is itself clearly a major alteration in his position, and arguably represents a substantial retraction on his part…
Now, three quotes from Logic of Scientific Discovery. First, his prohibition against ad hoc auxiliary hypotheses from pp. 82-83 (Section 20):
As regards auxiliary hypotheses we propose to lay down the rule that only those are acceptable whose introduction does not diminish the degree of falsifiability or testability of the system in question, but on the contrary increases it. … The introduction of an auxiliary hypothesis should always be regarded as an attempt to construct a new system; and this new system should always be judged according to whether or not it would constitute a real advance in our knowledge of the world.
Popper gives Pauli’s Exclusion Principle (no two electrons can occupy the same quantum state) as an example of a good auxiliary hypothesis.
On page 95, Section 26, Popper argues that statements of singular facts are hypotheses because stating them requires universals:
The statement ‘here is a glass of water’ cannot be verified by any observational experience. the reason is that the universals which appear in it cannot be correlated with any specific sense experience. … By the word ‘glass’, for example, we denote physical bodies that obey a certain law-like behaviour, and the same holds for the word ‘water’.
Finally, on p. 109, Section 29, Popper states that basic statements are left open for criticism and that they are not used to prove anything:
The basic statements at which we stop, which we decide to accept as satisfactory, and as sufficiently tested, have admittedly the character of dogmas, but only insofar as we may desist from justifying them by further arguments (or by further tests). But this kind of dogmatism is innocuous since, should the need arise, these statements can easily be tested further. I admit that this too makes the chain of deduction in principle infinite. But this kind of ‘infinite regress‘ is also innocuous since in our theory there is no question of trying to prove any statement by means of it. [I have added the italics in the last part of the last sentence for emphasis.]
The answer to these criticisms is that Popper is proposing a theory of conjectural knowledge, and the idea that he is altering his position has no textual basis. So scientific theories are conjectures, experimental results are conjectures, and refutations of our scientific theories are conjectures too. The way we keep science making progress is that scientists try to solve problems by proposing non-ad-hoc solutions to problems, including problems that arise as a result of doingexperiments. A non-ad-hoc theory is testable and it provides an improved understanding of the world if it is true. Scientific theories are controlled by criticism, not by proof and so the fact that we don’t prove anything is flatly irrelevant. No explanation is given in the article for why this position is unsatisfactory. And all of this is explained more clearly in some of Popper’s later work, including his book “Realism and the Aim of Science”.
Now criticism 2:
Popper’s distinction between the logic of falsifiability and its applied methodology does not in the end do full justice to the fact that all high-level theories grow and live despite the existence of anomalies (i.e., events/phenomena which are incompatible with the theories). The existence of such anomalies is not usually taken by the working scientist as an indication that the theory in question is false; on the contrary, he will usually, and necessarily, assume that the auxiliary hypotheses which are associated with the theory can be modified to incorporate, and explain, existing anomalies.
Any scientist worth his salt will try to solve the problem posed by an apparent disagreement between theory and experiment. He may do this by replacing the current theory or by proposing a specific non-ad-hoc auxiliary hypothesis, not just by saying ‘oh well, some auxiliary hypothesis will save my theory’s bacon’. Any scientist who doesn’t want to do this isn’t worth his salt.
On a related note, the author of the article claims that many Marxists wouldn’t be worried by the assertion that Marxism is unscientific because Marxists made ad hoc modifications. If the author of the article is correct in that accusation, then Marxists are a bunch of pseudoscientists.
The poor quality of the criticism section of this article is slightly surprising in the light of the fact that the author manages correctly to state Popper’s position earlier in the same article. Some criticisms earlier in the article, such as criticisms of verismilitude are more accurate, but they also fail to make contact with the most important part of Popper’s position – namely the idea that all knowledge is conjectural and is controlled by criticism. If this is the worst criticism philosophers have to offer, then Popperians don’t have much to worry about.
Thanks Alan, in your last para you report the same thing that I found years ago, before the piece was revised – the commentary in the body was ok and the critical comments at the end came out of left field.
Like you, I thought he spent too much time on Popper’s failed program to put a number on verisimilitude, I thought that was just a minor diversion, hardly worth mentioning after Popper conceded the error and gave up the program. One of my philosopher friends told me with malicious pleasure that Popper’s program had “collapsed” with that failure. I never even found the idea interesting. That was in the 1970s.
A couple of years ago I asked him how the Quinean program was getting on which he pursued through his career. He said they were still casting about for “criteria of cognitive meaningfulness”.
Note how the author has written “genuinely testable” and not just “testable.” So what is genuine testability? For something to be genuinely testable (and so genuinely scientific) it must be possible to determine whether a falsifying statement is actually true or false. In other words, there must be some infallible foundation to scientific testing for it to be genuine, otherwise science is, presumably, phony or counterfeit. Moreover, the author believes the absence of such an infallible foundation “poses a difficulty regarding the consistency” of Popper’s views. In other words, an infallible foundation is required for logical consistency — it is not something one can simply opt out of.
Justificationism is a litany of erroneous traditions regarding the means and ends of rational investigation, and they sustain themselves, in part, with the myth that such presuppositions are inseparable from logic and reason. In fact, this myth is itself part of that same justificationist tradition, and it is what makes it so damn near intractable!
Notice also how the author equates a free decision to accept a basic statement as arbitrary. Part of the justificationist tradition is the idea that freedom = arbitrary rational = authorised. This notion sneaks into social philosophy and science as freedom = anarchy and rational = central planning. For a justificationist, we must be compelled by some irresistible authority (usually pure reason or sense experience) to each position. The preoccupation here is with convincing others with forceful arguments, rather than the disinterested pursuit of truth. It often is accompanied with the sentiment: “if one cannot force another to accept one’s views with argument, then what is the point of arguing?”
Sorry for the triple post.
I think the hostility toward Popper comes from the intuition that he is cheating. He shows no reverence for the traditional rules of the game, so to speak, and feels at liberty to dismiss them when they are problematic. Traditional philosophers feel no such freedom; instead they compelled to follow the rules as though an inexorable part of human psychology.
The intution that Popper is cheating is little more than a feeling. To precisely explain the points of contention between Popper and themselves would require 1) an explicit analysis of the presuppositions of justificationism, and 2) contrasting those presuppositions with Popper’s alternative. However, the analysis never actually digs this deep. Justificationism’s survival depends on it being traditionally fused with logic and reason, and its implicit acceptence by all right thinking people. Accordingly, conventional criticisms of Popper all implicitly accept the presuppositions of justificationism, and judge him by those standards whether Popper himself agreed with them or not.
A difficult situation. Non-justificationism has been promoted by some of us in the Critical Cafe for a decade or so but the critics point out that nobody else in the philosophical world ever mentions the arguments about justification and the alternative. Bill Bartley has no profile at all.
One of the things you find in modern books on epistemology is something like “abduction to the best explanation”. Joe Agassi pointed out that this is a device to retreat from some of the errors that Popper identified without mention of him. (I suppose so the retreat does not become a rout!)
He also suggested that the philosophers are probably hoping to get through to retirement before some bright and articulate young people find Popper, more or less by accident, and start asking awkward questions in public.