I think the cons of ignorance outweigh the pros. Yes, ignorance can make a person more relaxed, less fearful, and sometimes more happy. At the same time, ignorance is a weapon that has been used by figures and movements throughout time to keep people under control and scare them into doing their bidding. Ignorance has also gotten millions to billions of people killed for millennia, with lack of scientific and medicinal/hygienic knowledge leading to countless disease outbreaks, as well as scares such as the Salem Witch Trials, the HIV/AIDS witch hunt in the 80's and 90's, and the anti-vaccine movement. Not to mention, many groups, including the mentally ill and disabled have been forced to endure brutal treatment methods and attempted exorcisms due to people centuries before not understanding mental illness and/or that the person is likely not being possessed or bewitched.

Excellent explanation. I like it!