From Tertullian’s Credo Quia Absurdum to Bohr’s Crazy Theories: A Rational Explanation of a Seemingly Irrational Idea

At first glance, Tertullian’s idea – that absurdity of a statement makes it more believable – sounds irrational, maybe appropriate for theology but definitely not for science. However, somewhat surprisingly, a similar idea was successfully used by the Nobelist Niels Bohr in theoretical physics – an epitome of rationality in science. In this paper, we show that this Tertullian-Bohr idea actually has a simple rational explanation. Specifically, if previous attempts to construct a theory which is consistent with what is perceived as common sense were unsuccessful, this implies that a true theory much contradict common sense – and thus, the fact that a given theory contradicts common sense increases the probability of its correctness. 1 Formulation of the Problem Historically first claim: in theology. The famous Latin phrase Credo quia absurdum (I believe because it is absurd) attributed to Tertullian, the father of Western theology, is actually not an exact citation: it is a paraphrase of a statement “prorsus credibile est, quia ineptum est” (“it is by all means to be believed, because it is absurd”) from his book De Carne Christi (On the Flesh of Christ); see, e.g., [4]. Somewhat surprisingly, a similar claim has been made in science. A scientifically minded reader may be tempted to dismiss this phrase as an example of irrational thinking of theology as opposed to rational thinking of science. However, a very similar statement was regularly made by a modern scientist, the Nobelist Niels Bohr. In 1958, after another Nobelist Wolfgang Pauli presented his and Heisenberg’s nonlinear field theory of elementary particles at a Columbia University seminar, Bohr famously said: “We all agree that your theory is crazy.