The phrase "such foolishness" means that someone has done or said something very silly or dumb.
Sentences with «such foolishness»
He'll tinker his reputation to do away with such foolishness someday. (kickstarter.com)
The Protestant ethic had the power for much of U.S. history to keep America's financial establishment from taking such foolishness with perfect seriousness. (religion-online.org)
This not the way that church should behave and they all should stop supporting such foolishness. (religion.blogs.cnn.com)