Based on Aesop's "The Belly and the Other Members of the Body."
Once upon a time, the various parts of the brain got together to discuss their contributions to the uniqueness of the human being. Each part of the brain thought the human ought to know that it was the most important in determining what it means to be human.
"You know, you really could not breathe without me," said the brain stem, the oldest part of the brain, at the very bottom. "Let me see how special you feel with no oxygen in your lungs!"
The diencephalon, the next part moving upwards, chimed in. "Yes, but I produce hunger pangs to let you know when to eat. Without me, you would starve."
The limbic system tried to speak, but the other parts rudely told limbic that its animal impulses, like lust and violence, created some of humankind's worst problems and would not listen to it.
"Everyone who has spoken so far belongs to what humans like to call the 'primitive brain,'" explained the cerebral cortex. "I am what makes humans unique. I present to you the four lobes of GREATNESS!" And each of the cerebral cortex's lobes then spoke:
"I am the occipital lobe. I am involved with vision."
"I am the parietal lobe. I receive sensory information from the body. But that is not all. I also take the letters the occipital lobe sees or the letters I feel (if using braille), and I form them into words. I then string together words to form complete thoughts." The other parts of the brain were impressed, and applauded. Though a bit of a braggart, the parietal lobe had the decency to blush.
The bar was now set higher. "You all know me," smirked the temporal lobe. "I'm all over the place. I do a little vision work, interpret most of what you hear, coordinate language, learning, memory, and even dabble in emotions. I'm a jack of all trades."
"Yes, but where would any of you be without me, "said the frontal lobe. "I do all the problem solving, decision making, and conscious behavior. I make sure you do not act in (sniff) inappropriate ways." Frontal looked directly at limbic while making this remark. "It is my use of reason that makes a human unique."
"Hey, wait," shouted temporal. "You forgot to mention that you, too, are involved with emotions. You are not just dealing in reason. Within your folds is the orbitofrontal cortex or OFC. I know because we're good friends and communicating all the time. The OFC integrates emotions into the decision making process."
"Yeah, OFC and I are buddies, too." said limbic. "It is always in touch with us 'primitive brain' parts. Before you make any decision to act, frontal lobe, the OFC has checked out how the person feels about the action needed and decided it is the best thing to do. You could not make that decision without consulting the parts of the brain responsible for emotions and those parts are all over the place. The old idea that human beings are mostly rational animals is outdated. Even you, frontal—the most rational part of the brain—consult emotions to do your job, which is making conscious decisions."
"In fact," the OFC piped up (it had been present all along, but preferred to work behind the scenes), "conscious decisions are not literally conscious at all. All decisions involve some unconscious processing that happens before the consciousness is even aware that a decision needs to be made. The unconscious thoughts are influenced by emotions, yes, but also strongly influenced by memory. We, the brain parts, ask ourselves, 'Have I encountered this situation before?' and use the answer to inform the decision. Therefore, the human's previous experiences and even their habits inform your actions on a conscious and unconscious level."
"So be careful of your habits and actions or deeds," said temporal.
"Likewise, be careful with your thoughts and words," said parietal.
"Wow! We are really wise when we work together," said the brain.