Philosophical Notes, No. 1: The Alibi Principle or Popper’s Falsificationism Falsified

Beginning herewith, at irregular intervals and in unsystematic order, I am planning to publish occasional philosophical notes, some brief, some a bit longer, but all inspired by the intellectual tradition of rationalist philosophy and critical of the rival tradition of empiricism and skepticism.

1. Popper’s Falsificationism Falsified

Karl Popper may not be in vogue among academic philosophers anymore, but he is still definitely the most influential philosopher among practicing scientists: among economists and other social scientists and, in particular, also among natural scientists. It is his philosophy that serves as the basis of their self-interpretation: their view of what it is that they are doing when practicing their particular trade or profession. As such, as the late Marburg philosopher Peter Janich has noted, Popper has probably been the most influential promoter of relativism in twentieth-century theoretical philosophy.¹

In a nutshell: According to Popper, apart from the formal sciences of logic and mathematics, all propositions aspiring to the rank of science must in principle be falsifiable by future experience (and even falsifying experiences are, strictly speaking, again only hypothetical, falsifiable falsifications).

What Popper rules out of the realm of science, then, is any knowledge that can be verified or that is immune from any possible falsification by future experience. That is, he claims that there are no such things as verifiable or necessary truths concerning the real, empirical world or, in Kantian lingo, that there are no such things as certainties or “synthetic a priori” propositions.

There are numerous problems with Popper’s philosophy. But this is the central one: What about Popper’s “falsificationism” itself? If the adoption of his views is no more than some arbitrary linguistic convention of how to distinguish “science” from “non-science,” then this is hardly a solid foundation for anyone’s philosophy. Conventions are conventional. Why, for what reason, then, should anyone accept this view of the world rather than another?

Yet if Popper’s view is taken seriously instead as an empirical statement, i.e., as some in-principle falsifiable hypothesis, it is easily refuted. A single counterexample—a single example of knowledge concerning something fundamentally “real” and “empirical,” and yet non-falsifiable or “a priori” true—is sufficient to bring the entire falsificationist edifice crashing down.

Janich has called this crucial counterexample the “alibi principle.”² Known to everyone who has ever watched or read a detective story, it states: A person can at different times be present at one and the same place, but no person can at the same time be present at two different places. No one, in any trial before a judge, would ever call this principle into doubt. It entails non-falsifiable knowledge about the real world. (Only in science fiction could things possibly be different.) Using Ludwig von Mises’s terminology, we could also consider the alibi principle as a law of praxeology. It is not just a formal or formalistic truth, but an a priori truth concerning empirical reality or, if you will, a necessary law of nature.

Thus: Popper’s falsificationism is falsified.

Related

• Hans-Hermann Hoppe, “Reflections on Method: The Proper Study of Man” (Mises University 2023), based on “On the Proper Study of Man: Reflections on Method,” Quarterly Journal of Austrian Economics 26, no. 4 (2023)
• Hoppe, A Theory of Socialism and Capitalism (Kluwer, 1989), ch. 6, “The Socialism of Social Engineering and the Foundations of Economic Analysis”
• Hoppe, “In Defense of Extreme Rationalism: Thoughts on Donald McCloskey’s The Rhetoric of Economics,” Review of Austrian Economics 3 (1989), reprinted in The Great Fiction, 2d expanded ed., ch. 18
• Hoppe, Economic Science and the Austrian Method (1995), esp. “On Praxeology and the Praxeological Foundation of Epistemology”

1. Peter Janich, Kultur und Methode: Philosophie in einer wissenschaftlich geprägten Welt (Frankfurt am Main: Suhrkamp, 2006), p. 162. [↩]
2. Ibid., p. 38. [↩]