"Foolishness" means behaving or thinking in a silly or unintelligent way, lacking good judgment or common sense. It refers to doing something that is not wise or sensible. Full definition
If I'm president for X number of years, and there's a wave of change in the next election cycle, my like - minded justices serve as an enduring bulwark against out of control foolishness of those who don't agree with my own irrefutable wisdom. (politics.stackexchange.com)
This is representative of an age of foolishness in which the sacrifices are made by learners who desire and need to learn, but see no motivation in learning that stems from curiosity and a very human love of learning. (elearningindustry.com)