Despite his great respect for Hippocrates, Galen and Aristotle, the three divine figures of medicine and philosophy in early Islam, he felt free to criticize and oppose their opinions (e.g., he wrote a book titled Doubts on Galen) if he felt he had adequate proof for his opinions. In his own words 'philosophy demand that you do not submit [intellectually] to your teachers, for that leads to stagnation of knowledge'.
Believe it or not, his criticism of the three learned ones earned him a lot of enemies in the academia of the Muslim world at that time, but could not cloud his influence as he continued to be a revered and reprinted author in medicine until the 18th century in northern Europe especially his book on infection diseases (You can read more about Al-Razi here).
As a medical professional myself, a message he wrote to a student of his leaving for a job in a distant royal court was unbelievably impressive in how modern it is. He was teaching his student (a budding new attending) not only the morals, and ethics of medical practice, but also on the psychology of 'VIP patients' and extended the scope of his advise to teach the student about life and politics in a royal court and how to handle it as a physician.
That lead me to another book of his called "Medicine of the Soul", an short treatise on psychology and psychiatry that also has the feel of a modern self-help and self-improvement book. I liked the the section on Anger very much that I decided to translate it and share it on the blog. I hope you would like the structure and the flow of logic, starting with the practical and mundane, culminating in a great sublime conclusion that has far reaching significance today as much as it had eleven centuries ago.
On conquering angerAnger was created into the animal so it could revenge on other harmful creatures. That trait in excess, which leads to the loss of the control of reason, would inflict more harm on the angry creatures than on the ones that made them angry.
For that reason, the wise person should keep reminding themselves of situation of those whose anger lead them to bad outcomes, either immediate or late. Then they guide themselves to imagine those bad outcomes when they themselves are angry.
Many of those who get angry can end up punching, or butting heads, thus bringing pain onto themselves sometimes more that what they inflict on the other. So many times I have seen a man, throwing a punch against another’s jaw, suffer from broken fingers that may take months to heal, when the one that received the blow did not get nearly as much harm.
And I have seen those who get so angry and screaming that they started coughing up blood, resulting in breathing problems that may lead them to their death.
I also became aware of people who, in their times of extreme anger, excessively punished and harshly abused their family, children or their loved ones with what they regretted for a very long time. They may have even been unable to repair what they damaged in their lifetime.
Galen [a ancient Greek founder of medicine] has even mentioned that his own mother [getting angry if she is unable to unlock a door] would jump at the lock and start biting on it in anger.
And, by God, their does not seem to be much difference between the one who loses his mind and his poise in anger, and the one who is actually crazy.
And the more one remind themselves of these things when they are calm, the more likely they would remember it when they are getting angry.

As for those who have done such unpleasant things when they were angry, they need to be informed that anger got the best of them because they lost their reason, so that they train themselves not to act in times of anger except after contemplation and patience. That way they would not get afflicted, when they thought they were punishing another person. And that way, they would not share with beasts their nature of unrestrained behavior.
He who wants to punish others need to be free from four attributes at the time he inflicts punishment: free from pride and hatred towards the one they are punishing, and free from the opposites of those two attributes. If he has the pride and hatred, revenge and punishment will exceed the extent of the crime, and to have the opposite of those two, revenge and punishment will not measure up to the extent of the crime.
A wise person who educates himself about these thoughts, and trains his instincts to follow their guidance, will have their anger and revenge fairly meted, and will be safe from harming themselves, in soul and in body, soon after they get angry or much later.
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