Corruption is a human condition, a poison which all humans are capable of. When we are expressing our Buddha nature, we are incapable of corruption because we are motivated by compassion.
So how does corruption come into being. I believe that the basis for this is fear and a poor relationship with our own Buddha nature. We become convinced that the only way we can be happy is to be "better than". This is delusion. A person who violates others for his or her own gain is corrupt. This can occur on an interpersonal level or globally.
Interpersonally corrupt people are motivated to take advantage of others. They feel that they need to prove their "dominance" of others by making others feel small or less than. Unfortunately this feeling can only be fleeting because it is not real. So the corruption escalates or humility takes over when the corrupt person hits a bottom of sorts.
With addiction we get a false sense of power from the sensation of the "high". Most of our using times are spent chasing that original feeling of false equanimity that we feel in the early days of using. Since this is impossible to achieve, we then become ego driven to avoid the feelings of "incomprehensible demoralization" that our using causes. We are in aversion of the pain of our condition and aversion is one of the primary causes of suffering. This is a downward spiral that "gets worse, never better". Usually a person is ready to enter recovery when they realizes that they are living in a hell realm of addiction. They realized that this is not living, and there us usually a moment of clarity which involves a fervent desire to be truly alive. It can come after a near death experience or it can come for just being "sick and tired of being sick and tired".
We learn about the "horse thief" analogy once we find our way in sobriety. We learn that while using most of us are sociopathic. We lie cheat and steal as a way of life. Once we get sober two things can occur. We can become true to the traditions of recovery and become upstanding citizens or we can become a "sober horse thief". This is better known as a person who is a "dry drunk". This person is corrupt. Even though he may not use or drink, she may take advantage of others or will try to exert power and control over others. This person may have other behavioral addictions that have not been addressed such as sex addiction or codependency. These character flaws cause the person to live a life full of resentment and a drivenness to achieve a false kind of happiness devoid of compassion.
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On a social or global level this tendency is just multiplied. It congeals with others of like mind. Sometimes it is called congress or the senate, sometimes it is called the corporation. Humans are drawn to form systems because we are social animals. These systems become corrupt because they are made up of individuals who lack true compassion. Occasionally we see a politician or a corporation that seems to be built upon compassion. It was Dennis Kucinich who proposed the development of a "Department of Peace"...he was laughed at for that. There are many companies who function on a more compassionate basis like Ben and Jerry's Ice cream....but they struggle and often have to sell to a less compassionate corporation who has "success".
The only way to heal from corruption is to understand that it is built upon delusional power and can only bring about unhappiness and suffering. We must become committed to principles of compassion and the end result will be happiness and humor. Just look at the Dalai Lama who most of the time is very goofy and childlike while running his beleaguered nation that was taken over by a corrupt country. He displays wisdom and skill and continues to be healthy and shows very little anger. He is a model for all of us whether we are people in recovery from whatever, or corporations or even nations.