Under two decades ago Karl Friston introduced the world to his Free-Energy Principle. Since then, multiple papers have come out that neatly explain aspects of existence (especially when combined with the field of cultural evolution and Donald Hoffman's Interface Theory of Perception) that have been hitherto separated. In this series, we'll walk through how the papers 'Uncertainty and stress: Why it causes disease and how it is mastered by the brain' and 'REBUS and the Anarchic Brain: Toward a Unified Model on the Brain Action of Psychedelics' present a model that fits well with aspects of Buddhism, Daoism, Pyrrhonic Skepticism, and Stoicism. As a treat, we may get a taste of animism in our stroll, and we just might run into the likes of the Desert Fathers and Sufism on our way.

We'll start with uncertainty and stress.

The world changes. We do not know how the world will change, just that it will change. People are little worlds in the world, and there is pain when the world changes because it reminds you that you and the world are not the same.

Pain comes from being very surprised. The pain tells you to catch up to the world, so you won't be surprised by the same things tomorrow. If you don't know how to catch up to the world and you feel you must catch up to the world, there is more pain. If you are used to catching up to the world and feel like you catch up to the world as much as you can, there is less pain.

How you deal with surprise decides how much pain you get when something surprises you. The more alright with being surprised you are, the more alright you are with change. The more alright you are with change, the less surprised you are when things don't go like you think they will.

The less surprised you are when things don't go like you think they will, the more full of life you are.

Three things decide how you deal with surprise: learning, how you look at things, and how you get used to change. How you look at things decides how you learn.

When people are faced with very surprising changes, they enter a state of fear where they think they're going to get kicked out of their group or die at any moment.

People hope that by finding the tiny thing that stopped them from seeing the thing that surprised them before it happened, they will know what to do later. When they're looking for the tiny things, they do not know what to do.

Not knowing what to do causes a lot of pain when you are in a state of fear.

If you do not find the thing that surprised you a lot in a way that caused you pain and you enter this state of fear and stay in this state of fear every day for a long time, you are caught in this state.

The longer you are in this state of fear, the easier it is for you get sick and die.

Every second we get new things from the world coming in through our eyes, hands, ears, nose, and so on. Through this, we make a story about what is outside us. Through these stories, we make a story that makes it easier for us to tell when something we care about more in the world is going to change. Some stories can come about because of many different things, so finding one thing to explain our newest story is actually very hard.

Because of this we have to pick one of our older stories about how the world works that will help us move in the world, since if we had to make a new story every second we would not move as much as we need to move to live.

Every second, you put your old stories together with the senses that are coming from your eyes, ears, hands, feet, nose, and so on. The old stories come from the top, and the senses come from the bottom.

When your old story of the world does not fit with the stories you are getting from your eyes, ears, hands, and so on, you might make a newer story about the world that does fit with the new things that are coming. Sometimes you might just change something in the world so that it fits. Say you want water in your room but your eyes, nose, and hands tell you there is no water. You might go to the living room and get some water and bring it back to your room.

Looking around for new things to sense makes it harder to keep old stories now, but makes it easier to have a better story that will last a long time. Staying away from new things to sense makes it easier to keep old stories now, but will make it easier to be surprised by a new thing later. So it is nice to both look around for new things a little and stay away from new things a little. How much is too much of one or the other rests on how much the world is changing and how good you are at seeing how much the world is changing.

We spend a lot of time looking for how to move next. In every second we are feeling out how our body is (and where it is in the world), where we can go, and where we think we should go. We pick the story that will help us get from where we feel we are to where we think we should be. The part of our brain that tells us where we are sends the story of where we are to the part of the brain that is getting new stories from our senses.

When we are surprised, we send more energy to our brains so that it can look over smaller bits of the stories it tells. The more surprised we are, the more energy we send to the brain. This makes us pay more energy to the brain than other parts of our body, so as soon as we figure out how to live with the change, we go back giving less energy to the brain and putting more energy in the body. If this does not happen, things are off. One thing gets too much, another thing gets too little, and the whole body finds it harder to change when the world changes.

Every time things change (and they're always changing), our brain needs to know how much of our story it needs to get from lower in how it orders things- closer to our senses, and how much of our story it needs to get from higher in how it orders things- closer to the stories we've used most. So over time we learn when to listen to the story from the higher side, and when to listen to the story from the lower side. Each story from the top comes from how little the story of Now surprises us and how much we think it will surprise us. If we think it will surprise us, we listen more to the bottom- closer to the new stories we get from our senses. We don't listen to those stories all the time because we would have to pay a lot of energy to our brains and we need that energy for other parts of our body, so we only listen to them when we think the stories from the top are not working to lower how surprised we will be.

From living, some people learn to get used to change (the paper calls them 'habituators'), and others don't. People who are used to change are not hurt as much by surprise. These people who are used to change get used to change by making their stories very big, instead of very small. Since their stories are big, they can fit more new things in them, so they are less surprised by new things. These people who get used to change become more sure of themselves as they change more. They hurt less from being surprised. They feel more like they are always true, so they do not feel the need to say or do things to make it look like they are true. They feel like they can meet the world wherever it is, and wherever it will go. This lowers their chances of getting sick.

Maybe this is beginning to sound like something you know, so here's where we'll stop. Next time, we'll talk about Buddhism, and how this has to do with that.