Bernardo's got an excellent new blog post up on his site titled , in which he diagnoses Intellectual Fundamentalism as if it were a medical disorder. I actually started writing something similar here once, (which I eventually deleted without posting), but Bernardo has done a much better job of it than I could have.
A sufferer of intellectual fundamentalism, on the other hand, looses interest in intended meaning and focuses, instead, on the form of the logical and grammatical constructs used by his interlocutor. The patient will fixate obsessively on what is said, losing sight of what is meant. When a logical flaw is found in what is said, the patient will construe it as sure evidence that his interlocutor is unworthy and completely close himself up to the intended message. This fixation on form above intended meaning is not only detrimental to the patient – who misses out on much of the subtlety and nuance of what others try to convey to him, particularly those who have most to contribute for seeing the world in a different way – but also to his interlocutors: it is frustrating for family, friends and acquaintances to interact with someone who insists in finding flaws in the finger pointing at the moon, instead of looking at the moon.
Depending on the degree of advancement of the condition, the denial of all forms of cognition other than the intellect usually grows to become a fixation. At this point, if still left untreated, the condition can further evolve into a hero syndrome, which drives the patient to try and "save the world" by attempting to eradicate all human activities, views, and general outlooks that do not conform to intellectual value systems.