I've heard a quote very similar to what you stated in the OP.
Here's a quote I like.
A fool thinks himself to be wise, but a wise man knows himself to be a fool.
Regarding the dangerous comment, anyone can be dangerous. We all have the potential to be a hero or a villain, kind or cruel, caring or apathetic. Virtually anyone will screw you over if anything they value can be gained for themselves. If you're more intelligent you are more capable of resisting certain social influences and situations that can make any of us indifferent to the suffering of others or even perpetrators ourselves. One example is that someone who lacks intelligence is more likely to fall into the clutches of "group-think". This is what cults are based off and the fact we all want to belong to a group and be accepted. Look at what Charles Manson's followers did based upon his instruction.
Well, people with conceptual and perceptual abilities make it into power,(politics) and make stupid decisions that affect many people and systems. Versus the idiots in riots who shout loud and get a crowd of sheepsters going.
Don't play with "tools" unless you know what they do on all fronts :tongue: