 A second worry for the logical learning approach points to an internal tension: On the one hand, this approach has to work by permitting a less-than-certain credence in a logical fact such as \(E_\textrm{logical}\), and that amounts to permitting one to make a certain kind of logical error. On the other hand, this approach has been developed on the assumption of Probabilism, which seems to require that one be logically omniscient and make no logical error (as mentioned in the tutorial  section 1.9).  van Fraassen (1988) argues that these two aspects of the logical learning approach contradict each other under some weak assumptions.