What does being crazy really look like?

In making decisions about who to engage in discussion one is often drawn to posts which are the most obviously wrong. This is where it feels there is the most bang for the buck, that a simple explanation of no more than a few sentences and taking less than five minutes will remedy obvious error.But after a few exchanges one discovers that it isn't so simple, and it might take days or even weeks before one throws up one's hands and declares, perhaps just to oneself or perhaps publicly, "This guy is crazy, there's no reasoning with him, I give up."I believe that craziness is darn hard to recognize. Unlike the obvious craziness of characters from books and movies, an individual's craziness is so completely woven in to the fabric of reality that it seems that one is just experiencing a disagreement rather than interacting with insanity.I'm convinced that some of the craziness we see here is dementia, an inability to keep facts in mind or put them together into consistent narratives, but the rest of the craziness is genuine and very difficult to conclusively diagnose as true insanity, albeit often of a very mild and harmless sort.Some might remember John Davison, and I think he's a good example of true insanity. Many of us engaged in discussion with him for months and even years. As his condition worsened he was eventually banned from the several boards where he participated, including here.And of course we're all familiar with Dennis Markuze aka David Mabus, who is so genuinely crazy that it is recognizable by reading just a single post. But this kind of obvious craziness is the exception.Is there a way to detect craziness early so as to avoid wasting all the time? Or is engaging the craziness profitable in that it brings many rational responses that couch the issues in terms that match reality?--Percy

To thoe who replied to my original post, I read them all, thanks. I'm going to reply generally.I agree about the importance of posting for the benefit of the lurking audience. And just maintaining a record of accurate information is important, too.From a psychological standpoint, insanity is so varied and infinitely nuanced as to defy simple characterization, but I don't believe this is true in a discussion board context. I'm wondering if it is possible to tell early when one is wasting one's time.I agree that in some cases there is simple fun in engaging insanity. Certainly we all enjoyed discussions with mild-mannered Brad (he goes back a ways, many might not recognize the name, he had a form of schizophrenia). Even if we rarely understood him he was generally treated with respect, I think because his ideas were honest and without agenda or judgment.I guess my simple rule is that once one starts explaining logic or English then it is time to give up, not that I follow this rule all the time. But are there other helpful signs?--Percy