Diagnosing the Tortoise

The empirical study of logical reasoning holds a special place in my heart; a warm, fuzzy spot for something endearingly odd. I came across this abstract today:

"Conditional reasoning studies typically involve presenting a major conditional premise (If P then Q), a minor premise (P) and a conclusion (Q). We describe how most fMRI studies investigate reasoning and point out that these studies neglect to take into consideration the temporal sequence of cognitive steps generated by the interaction of the premises. The present study uses EEG to address this issue and compares the processing of the minor premise P when it is presented before vs. after the conditional statement (P; If P then Q vs. If P then Q; P). When the minor premise comes after the conditional statement and matches the antecedent its processing results in a P3b component, known to reflect the satisfaction of expectations, and in two later components, a PSW component and a CNV component. These two components are discussed in light of a conclusion generation phase and a maintenance phase. We also investigated the effect of violating expectations through the presentation of a minor premise that mismatches the antecedent of the conditional statement (If P then Q; R). The data indicate that the processing of such a premise yields an N2 component which is known to reflect perceptual conflict." (Link.)

So, we take the Tortoise, cover his scaly head in electrodes, observe that he is not registering a fulfillment or violation of expectations, call him aspect-blind and arrange to stimulate the proper neurons. What would Achilles think of that? (He'd probably be quite pleased; the Tortoise is annoying.) We don't need to justify deduction; we need to cure the Tortoise. While it's fascinating, and potentially practically helpful (for the handful of people who are inference-blind, if in fact there are any), I don't think it solves the problem of explaining how deductive inference is justified. Not, that is, unless we want to revise our theory of logic to make the foundational notion that of fulfilling expectations.