A holon is a wholeness and a part of a bigger whole at the same time. You are a holon. Your organs are holons within you. Your health depends on the harmony and cooperation between your organs. It is the higher organisation that you represent that takes care of that.
But you are also a part of a bigger holon. In the book Seven Arrows by Hyemeyohsts Storm about native Americans, the Medicine Man was asked about the origin of disease. He answered, when the first man acted for his own benefit in contradiction to the benefit of the tribe.
We all are parts of bigger holons. The family, the professional community, the nation and human kind are some of them. When we act to our own good but with a bad influence on the bigger whole, we create disease at that level.
As humans start to live out the time of the ego more and more people start to make a priority to make decisions that benefit the whole community even if it is negative for them personally. (Not like the guy on the picture trying to enter the tube before people can be let out)
You can train yourself when in a group of people by asking yourself what is the best benefit of the group, what can I do for the whole, what is most needed, is there some work nobody likes to do that I can do?
When driving your car, you can ask to be part of the whole traffic and perhaps it is of better benefit if others can drive ahead of you, perhaps somebody on the road that day needs to be taken extra care of in a subtle way.
When you meet somebody, ask yourself what can I say to this person that is for the best benefit to our common community.
Many people still have the main split between their animal and human nature and act out of fear, anger, egoism etc.
More and more people start to transcend that split to become a question of me or the bigger group. The more you act on behalf of the group the greater is your degree of holonity.
Step by step you will feel you belong to a bigger holon, with a much higher benefit, with a deeper state of peace and much less to worry about.