Back in the times of the Ancient Days when Humanity first crawled out the Primordial Slime, and later on began walking on twos, it is assume that our standard definition insanity, are ancestors pretty much fit this profile perfectly.
Whenever someone died back in the days, people would always claim that they would heard voices coming out of the relatives that were had just died. They would hear voice for hours until they were no more, a standard psychosis for the mentally insane. Combine that ritualistic killings and suicides, being being apparently conducted or controlled by Shaman Leaders who believed that an Spirit, Deity, or an Animal Lord was demanding it, and you have a rather archaic rule. That's because back in the day our ancestors had a much more balanced out brain, the left side was equally as powerful as the right side. Yet somewhere in our Evolution, our left side of the brain that seeks logic and reason got stronger and we lost the ways of how to communicate to the dead.
This was of course no instant mind you, it happened gradually over time. Time after time, the right side of our brain, our spiritual side began to lose its own power, and things like communicating to spirits, the dead, and animals... pretty much lost. This drove many individuals crazy as it turned out. Many people would build statues with opening mouths just so they could possibly hear a voice that would help them speak to there loved ones, but alas this was futile. As discussed the right side was weakening to the left side over time.
Eventually, we simply lost our ability to speak to these apparent "Ghosts" though how and why this is Evolution took place is unknown. Could it have simply been automatic that we speak less to spirits, or was it by some form independent will by our Ancestors? Who grew tired of being dominated by the Unknown Forces of Beyond and decided that they wanted to dictate all of society through there rule and create order out of the endless Chaos that stood in front of them. We do not know, but it is interesting to not how quickly society expanded as soon our Right Side of the Brain... The Artistic One was suppressed over Lefty's Logic and Reason.
We remain superior from our former selves, but rather Hollow and Empty. Though our Sciences have brought many wonders, and technology has almost never been better, the poisonous greed and meaningless materialism that has tainted the human mind is tearing ourselves apart. A little Madness... Natural Madness returning to our Society would really help get things to... Evolve.
I'm sorry this has nothing to do with anything I have currently been discussing, it's just that I've been wondering on the Natural State of Madness...