History of Humans: from an extra-terrestrial's notebook
Human history can be studied by dividing it into three stages. Ancient, quasi-modern, and modern. These can be differentiated by the methods, the people have been using to keep themselves busy. (Why they need to do so, is another topic that merits attention)
As it is well known by all except perhaps the humans, the above mentioned need is served better by the irrational. In ancient times, members of the human race, common people, might have had quite a free life, since every different opinion stood to be equally irrational as any other one. Since people in those times entertained many colorful ideas about natural and magical entities like plants, animals, and other objects of interest, there would have been no dearth of such ideas. Obviously, there was no difficulty in keeping themselves busy.
As time went by, some of those (irrational) thoughts could have turned into real, effectively making those ideas useless, posing a formidable challenge. Well, human race met the challenge, and their incessant efforts to replace those lost (irrational) ideas resulted in magnificent thoughts and great things. This long period of struggle, where human race seem to have excelled in every sphere of social life, arts or science, or, war or peace, can be termed as the quasi-modern era. And humans started leaving behind signs of their existence, since they started to resort to such things as professions and pastimes to keep themselves busy.
Now comes the modern era, when the race is rather free to enjoy the fruits of past centuries of labour. But no, they won't. The developed society is far short of irrational ideas, the excellence of previous eras having wiped off many well serving ideas of such nature. Having no fresh ideas of this genre, those people resort to reinforcing whatever irrational thoughts remain. In that process, they might make their own condition more and more unbearable, leading to extermination of the race altogether. Of course they can investigate deep into the need for the irrational, that is, the need to keep themselves perpetually busy. By doing so, a good solution may be arrived at, which will alter the race for ever. Human race is now faced with that choice. They need to react before the irrational engulfs them fully.