There are four types among temperaments: 1. Easily angered and easily appeased--his gain outweighs his loss; 2. Slow to anger and slow to be appeased--his loss outweighs his gain; 3. Slow to anger and easily appeased--a chasid; 4. Easily angered and slow to be appeased--a wicked person.
Easily angered and easily appeased--his gain outweighs his loss. Such a person is less stressful to those around him since they know that his anger will soon pass. Not so in the case of one who is slow to anger and slow to be appeased. His anger may not flare often, but it is much more destructive when it does surface.
Some people are impetuous--easily angered and easily pacified. Some are by nature more deliberate--they are slow to anger, but once angered are not easily appeased.
One who is slow to anger--i.e., a deliberate person--yet forgives quickly (an impetuous act), is obviously defying his nature and is therefore called pious. One who is easily angered--i.e., an impetuous person--yet does not forgive easily, is clearly a wicked person since he defies his nature to act wickedly.
Anger is caused by arrogance. An arrogant person takes offense easily. The first two types described in the Mishnah are certainly flawed, but their temperaments reveal that they are not truly arrogant:
The first type is sensitive to his own feelings--and is therefore angered easily--but is also sensitive to others and therefore is appeased easily.
The second type is not sensitive to others--and therefore is not appeased easily--but at the same time he is not sensitive to his own feelings--and therefore is not angered easily.
The above two types are therefore not considered wicked since their arrogance is relatively benign. The third type is one who is oblivious to offenses committed against him--not easily angered--yet sensitive to the feelings of others: easily appeased. He therefore represents the ultimate in humility and can truly be called a chasid.
The fourth type, however, is hyper-sensitive regarding himself--easily angered--yet insensitive to others: not easily appeased. He thus represents the height of haughtiness and is called wicked.
Alternatively, the Mishnah refers to one whose nature is to get angry but who overcomes his temperament and acts properly. Still he is called "wicked," by the standards of Avot, since he must strive to change his nature.
Holtzberg Memorial Edition