The term "great spirits" is often used when refering to
Albert Einstein's quote: "Great spirits have always encountered
violent opposition from
mediocre minds."
In other words, anybody who wants to change things and improve upon them will undoubtably encounter violent opposition from those who support the status quo. Most people also tend to be scared of those who are smarter and more clueful than they are, while being content in their cluelessness.
An example is the violent opposition which many geeks encounter in various environments, most notably public schools and particularly high school from the mediocre minds which inhabit those realms.