Then you witness yourself or watch people pretend to know everything in a debate: it's a funny front, but also necessary, a mass hallucination of total knowledge or total ignorance that, somehow, prevents the argument from collapsing into silence or chaos and forgoes the death of debate. Democracy thrives, even, on an ability to circumvent the limits or shortcomings of what is known, collectively and individually. (How glib.) Just to keep things moving: obviously is both negative and positive. The contemporary travesty of "opinion" is a high-profile victim of this tendency as consuming malaise. Nevertheless, an argument is the most necessary form of human interaction after laughter and sex.