Fallibilism

Fallibilism is the philosophical doctrine that absolute certainty about knowledge is impossible; or at least that all claims to knowledge could, in principle, be mistaken. As a formal doctrine, it is most strongly associated with Charles Sanders Peirce, who used it in his attack on foundationalism, but it is already present in the views of early philosophers, Xenophanes, Socrates and Plato. Another proponent of fallibilism is Karl Popper, who builds his theory of knowledge, critical rationalism, on fallibilistic presuppositions. In recent times, the concept has also been employed by Willard Van Orman Quine to attack the possibility of analytic statements.

Unlike scepticism, fallibilism does not imply the need to abandon our knowledge - we needn't have logically conclusive justifications for what we know. Rather, it is an admission that because empirical knowledge can be revised by further observation, any of the things we take as knowledge might possibly turn out to be false. Some fallibilists make an exception for things that are axiomatically true (such as mathematical and logical knowledge). Others remain fallibilists about these as well, on the basis that, even if these axiomatic systems are in a sense infallible, we are still capable of error when working with these systems. Moreover, according to Gödel's incompleteness theorems, to find a complete and consistent set of axioms for all of mathematics is impossible, That is, even mathematics has its own paradox like the Barber paradox. The theory that it was impossible to know a truth with certainty was the basis of the educational movement lead by people like John Dewey and was called the pragmatist movement.

The critical rationalist Hans Albert demonstrated the impossibility to prove any certain truth even in the fields of logic and mathematics. See his Munchhausen-Trilemma illustrating the hopeless situation to justify all your means to justify any certain truth. Even if fallibilism is inevitable Albert does not fall victim to relativism or scepticism.

Moral fallibilism
Moral fallibilism is a specific subset of the broader epistemological fallibilism outlined above. In the debate between moral subjectivism and moral objectivism, moral fallibilism holds out a third plausible stance: that objectively true moral standards exist, but that they cannot be reliably or conclusively determined by humans. This avoids the problems associated with the flexibility of subjectivism by retaining the idea that morality is not a matter of mere opinion, whilst accounting for the conflict between differing objective moralities. Notable proponents of such views are Isaiah Berlin (value pluralism) and Bernard Williams (perspectivism).

Selected reading

 * Charles S. Peirce: Selected Writings, ed. by Philip P. Wiener (Dover, 1980)
 * Charles S. Peirce and the Philosophy of Science, ed. by Edward C. Moore (Alabama, 1993)
 * Traktat über kritische Vernunft, Hans Albert (Tübingen: Mohr, 1968. 5th ed. 1991)