Dennis Hackethal’s Blog

My blog about philosophy, coding, and anything else that interests me.

Published · revised (v3, latest) · 3-minute read · 2 revisions

Fallibility Table

In his book The Myth of the Framework,1 Karl Popper presents what has since become a famous quote of his (page xii):

‘I may be wrong and you may be right, and by an effort, we may get nearer to the truth.’

This attitude is at the heart of his philosophy, critical rationalism. We may call it the fallibilist attitude.

When we have a disagreement with someone, whether he has this attitude tells us a lot about whether we can reasonably expect to make progress in this particular disagreement. If he does not have this attitude regarding this particular matter, and assuming that we do, that doesn’t necessarily mean we can’t make progress together in other areas or that we can’t make progress in the same area if he changes his attitude. Nor does it mean that we can’t learn from interacting with someone like him.

Following Popper, we can never know whether we’re right about anything.2,3 There is no criterion of truth. That’s why he’s careful to say “I may be wrong” and “you may be right” (emphasis changed). But we can think through different scenarios in which we simply postulate who is right and who is wrong.

There are sixteen different scenarios in which two people with conflicting views about a particular issue can find themselves. These scenarios differ in who (if anyone) is right about that particular issue and who (if anyone) has a fallibilist attitude. The ‘fallibility table’ below lists all possible scenarios.

You’re right? They’re right? You have the fallibilist attitude? They have the fallibilist attitude? Joint progress possible?
1 no no no no no
2 no no no yes no
3 no no yes no no
4 no no yes yes yes
5 no yes no no no
6 no yes no yes no
7 no yes yes no no
8 no yes yes yes yes
9 yes no no no no
10 yes no no yes no
11 yes no yes no no
12 yes no yes yes yes
13 yes yes no no no
14 yes yes no yes no
15 yes yes yes no no
16 yes yes yes yes no

A few things to note about this table. First, you may notice that joint progress (again, in a particular matter) is only possible if both parties have the fallibilist attitude, as shown in rows 4, 8, and 12. However, there is one scenario, pictured by the last row, in which joint progress isn’t possible despite both parties’ fallibilist attitude – when both parties are right. So there’s an interesting asymmetry there. (If it were symmetrical, every fourth row, including the last one, would read ‘yes’ in the last column.) In other words, progress is only possible (broadly speaking) if two conditions are met: not only must both parties have the fallibilist attitude but at least one of them must be wrong.

Second, it is always possible for either party to regress instead of progressing or remaining stagnant.

Third, there are only three out of sixteen scenarios in which progress on a particular issue is possible. Solving problems together is often difficult. A lot depends on the fallibilist attitude.

In a critical discussion, you can test whether someone has the fallibilist attitude by asking them to steelman your view. Or you can ask them to think of reasons you’re right and they’re wrong. Doing so commonly causes them to do to the opposite, in which case they probably don’t (yet) have the right attitude. You can also ask them what would change their mind. Of course, you should be prepared to respond to the same questions.

Thanks to Logan Chipkin for commenting on a draft of this post. In addition to Karl Popper, David Deutsch has influenced my thinking on fallibility, especially in chapter 10 of his brilliant book The Beginning of Infinity. I’m also influenced by Elliot Temple’s Paths Forward.

  1. Popper, Karl. 2014. The Myth of the Framework: In Defence of Science and Rationality. United Kingdom: Taylor & Francis. (This reference was auto-generated by Google Books, except I moved the year to make it consistent with my other references.) 

  2. It seems to me that some of Popper’s fans have misunderstood him and taken this view too far. They think we’re never fully right about anything. For example, Brett Hall thinks “we cannot “speak the truth”.” But of course we can. Popper only says that we can never know whether we are right, and that we should expect to be mistaken. He does not say that we’re never right about anything. On the contrary, he quotes Xenophanes (see footnote 3), who says we can be right, and utter “[t]he perfect truth”, if only by accident – and I believe that people are right frequently, especially about mundane things where correcting errors is easy. They’re just never right about everything, about the entire Truth. Of course, none of this detracts from the desirability of the fallibilist attitude, nor does it mean we should try to find ways of being right, or proving that we are right. 

  3. For example, I have previously quoted Popper: “Every unambiguous statement is true or false (although we may not know whether it is the one or the other); […].” (Popper, Karl. 1983. Objective Knowledge: An Evolutionary Approach. Oxford: Oxford Clarendon Press. P. 55)
    The Xenophanes quote referenced in footnote 2 reads: 

    And even if by chance he were to utter
    The perfect truth, he would himself not know it;
    For all is but a woven web of guesses.

    As quoted in Popper, Karl. 2002. Conjectures and Refutations. London, New York: Routledge. P. 34


This post makes 1 reference to:

There are 5 references to this post in:

What people are saying

Ironic to cite Elliot Temple’s Paths Forward while not having any paths forward with him.

#427 · anonymous ·

What are your thoughts?

You are responding to comment #. Clear


Markdown supported. cmd + enter to comment. Your comment will appear upon approval. You are responsible for what you write. Terms, privacy policy
This small puzzle helps protect the blog against automated spam.