The Nervous System

When studying the function of the brain, it is helpful to keep in mind the following view of nature: looking at the immediate world around us, we could say that there are four main realms.

The first is the mineral world. This is what we can touch. The earth provides substance.

The next step up the ladder is the plant realm. On this step, life is added to substance. In other words it becomes living matter. Plants live in a world of rhythms, such as day and night, summer and fall. They exist in cycles of growing and wilting.

The next realm is the animal world. What is the added extra here? Try to answer for yourself the question: "what can animals do that plants cannot?"

Well, for example, animals can move and breathe with their lungs. They can use their senses. They have eyes, a sense of smell and taste. They have instincts, drives and perhaps passions. Animals are aware of their surroundings. The added extra on this step of the ladder is consciousness.

Now, what realm do you think we will enter with the next step? This is the human realm. What can we do that animals cannot? We can speak and walk upright. We can think and be creative and use our intelligence. We can judge. Above all, we have a choice in what we do. Therefore, we can behave differently from our fellow human beings. Each of us has a name. We are individuals, whereas animals belong to a group, like cows or tigers. Each cow has not got an individual name, but is part of the herd.

Animals do not think. For example, contrary to the popular saying, a cow will graze in a meadow and is unlikely to look over the fence to see whether the grass is greener elsewhere. It just follows its instincts and has no choice. A tiger has to kill for its food, but we do not say that every tiger is bad!

By being human, we have a choice in what we can or will do. This freedom comes with responsibilities. In the human realm, because of our free will, ethical judgments are made and we can talk about good or bad behaviour.

So, in addition to being alive like plants and conscious of our surroundings like animals, we are actually self-aware. The quintessence added to our realm is self-consciousness.

 (partial chapter)