To feel emotions is to be human. Expressing emotions is necessary in order to be mentally healthy. For example, Bottling up sadness internally does not help fix your sadness. Instead, Humans naturally cry in order to let the sadness out. This is why people usually feel better after they cry. Similarly, Anger must be expressed in order to maintain a healthy mental state. Therefore it would be foolish to hold anger. However, The different ways in which anger is expressed also determines if a person is a fool. Anger should be expressed, But lashing out in violence helps no one and only makes oneself the fool. In contrast, An angry person that expresses his anger through meditation would not be a fool. Regardless, Anger should not be held in.
Everyone gets angry. At some point or another. At least maybe just frustrated. But if you were to hold that anger towards someone, Or something, You are pretty much stating you are incapable of handling the situation properly. Like saying you are wrong to yourself over and over and you cannot calm yourself to move on.
To be angry is not necessarily to be human. The mere presence of anger is not enough to infer that something is human. Afterall, Throngs of species across the entire animal kingdom regularly feel anger. Are they human? Of course not. Anger is neither a sufficient nor necessary condition for something's being human.
Although we, As human beings have every right to be angry, It is ridiculous to let it blind our conscience. Being capable of holding back the anger to eliminate any potential urges to make destructive decisions is what differentiate a fool and a rational. Anger is an innate toxin. Only you can be the sole victor to defeat it.
Maintaining anger without any direction is without any doubt foolish. However, The importance of anger in directing conversations about rights and values is undoubted. Anger is the passion that fuels your fight towards freedom. Anger makes you go out on the streets asking for a change. If you are not driven by anger at injustice, Then what pushes you forward to make a change?