ZAMM and the follow-on Lila are both worthwhile reads. However, I was uncomfortable with Persig's (pervasive) discussion of insanity. He defines insanity as,

ZAMM and the follow-on Lila are both worthwhile reads. However, I was uncomfortable with Persig's (pervasive) discussion of insanity. He defines insanity as, roughly, holding beliefs that differ widely from those held by an overwhelming majority of society. There seems to be an explicit avoidance of physical causes for mental illness to the point of rejecting the idea that mental illness is an "illness" to be treated. His "insanity" is a natural result of pursuing complex paths of thought to their logical end (beyond where most people take them). Can anyone shed light about the current (medical) take on mental illness and whether it jives with what Persig has to say?