It is not at all coincidental that Darwinian psychology has the same difficulty explaining the unity and integration of human reasoning as Darwinian biology has explaining the unity and integration of irreducibly complex functions. Practical and theoretical reasoning is often irreducibly complex. A given argument has several well-matched, interacting reasons, and the removal of any one of them makes the argument break down.

The inability of Darwinian psychology to account for human reasoning is devastating to its pretensions to be a science. The prestige of science depends on the application of highly advanced practical and theoretical reason. A 'science' that is incompatible with such reasoning is therefore at odds with the very essence of scientific activity.

If the majority view, whether in government or in the scientific establishment, is wrong, toleration of dissent increases the odds that their errors will eventually be discovered. But even if the majority view is correct, as it often may be, it is more likely to be seen to be correct if it must defend itself against critics.