The world makes progress by lurching from one extreme to another while overcompensating for previous mistakes.
Book: Great Thinkers
This belief is from Georg Hegel, the 18th-century German philosopher. Nowadays, this is a pretty obvious phenomenon like what we can see in Politics. However, it's still pretty interesting to know that there's an observation from 200 years ago stating the same thing. Maybe that's why Hegel declared that "every era can be looked at as a repository of a particular kind of wisdom."
Hegel proposed that, in general, it takes three moves before the right balance, a process that he named the ‘dialectic’.
In his time, the example he pointed out is the improvement of governance, from the inherited traditional monarchy to the emergence of Napoleon, and finally to the modern 'balanced constitution' where popular representation balanced up with the rights of minorities and proper centralized authority.
In our times, the example in the books is our sensible attitude to sex. People in the Victorian era might impose too much repression, whereas the 1960s may have turned out to be too liberal. And maybe for these decades, we are finding the right balance between the extremes.