Let us start with a story; a story mentioned often in oriental literature. Maybe, Milinda Panha was the first scripture to mention this. In it, the monk Nagasena asks the Greek sovereign Milinda the simple question of "what is a chariot?".
“Then, explain sir, what that is. Is it the axle? Or the wheels, or the chassis, or reins, or yoke that is the chariot? Is it all of these combined, or is it something apart from them?”
A "chariot" is actually a model representing the form, the utilities, the combinations and the narratives behind them all. If you think, you would realise that the meanings of the word "chariot" (or for that matter any word) has been becoming richer as we age. This is a model, made richer by our experiences. This is what the Buddhists term pannati. Our brains have evolved to become model-making minds. It is inbuilt into our prefrontal cortex which has six layers (developed through millions of years of evolution). We sense through our senses and immediately make a model out of it. Why?
This is just my non-expert hypothesis. From an evolutionary point of view, thinking and planning homo-species could optimize the use of resources (including their own time). That made them successful adopters in many different ecosystems. That started making their minds evolve to do more modelling. It went on till we could no longer distinguish between model and reality. Every data carried by our sense organs are immediately converted to models. The more we experience the more complicated and sophisticated these models become. For example, when I see and taste a cheesecake for the first time, I try to compare it with other things I have had and seen before. When encountering a new object we all are like the five blind men who went to encounter an elephant. When I see or taste a cheesecake again I have the existing model of cheesecake which consists of all the cheesecakes I have eaten and seen and the milieu in which I did so. Every extra encounter keeps enrichening my model or pannati.
The models are then used in creating mental simulations. Just creating models as we encounter things is not enough. We do not encounter things often enough. Our brains have evolved to create models and, then, use these models to create mental simulations. These mental simulations are "thoughts". Evolution has made our brains extremely good simulation engines. We keep simulating all the time in order to create as much richness as possible about all the models we have. Recent brain studies have found that neural circuits tend to create almost 90% of the signal inside the circuit. Only 10% of the signal comes from outside. These simulations made humans extremely successful in the race of evolution. By the Red Queen Hypothesis, we kept on improving our modelling and simulating capabilities as quickly as possible.
The race of evolution has made us to model and simulate a bit too much. Remember, we evolved for millions of years in circumstances where the number of external stimuli was not a lot and it remained like that till the information age. Suddenly, we have too much information to process. We have too many people to deal with. We have too many emotions to work on. Our brains did not get time to evolve to handle this. They are getting saturated and, in turn, getting tired and sick.
What can we do? We can try to actively limit modelling and simulating.
1- Limiting modelling: We can try to actively feel what we sense without forming a model. It needs practice. For example, when we see a beautiful sunset, we can try not to see the sunset! Rather, we can try to directly perceive the components, trying not to name anything if possible.
2- Limiting simulation: This is what we try to do in mindfulness meditation. The trick, it seems, is not to actively try to control the thoughts/simulations. Rather, try to observe the simulation process. Try to observe each thought as it comes and goes. The Buddha gave a nice allegory. He told that the mind is like a naughty monkey trying to jump all over the place. Try to observe the monkey. That will make it shy and it will try to settle down!
It is funny that we all want to relax and not do anything. But, not doing anything in the mind (i.e. not modelling and/or simulating) is extremely tough. Evolution has made our brain extremely efficient modelling-simulating-engines. Meditation can help in changing the brain structure. Mindfulness can help us to stop saturating our brains!
