But human beings are not rational - not 98% of the time. Cognitive science has determined that overwhelmingly we do not engage in what we think of as conscious thought except about 2% of the time - instead we are driven by cultural narratives, childhood programming, the influence of media, and other subconscious impulses that run most of us like puppets. As I stated and supported with a citation in the OP, the belief that humans were rational was a central tenet of 19th century philosophy - but it's woefully outdated and antiquated because it's not remotely true.