Anger is a difficult thing to manage because too often it is upon us before we realize it - and then we face the task of having to hold it back - to keep it from rising to the surface and exploding. We are told in this passage that a fool always loses his temper. That means that he has no control over his spirit. Words like "always" and "never" are not used lightly in the Scriptures - so we see that someone who is always losing their temper - truly is a fool.
A very wise man once told me that the reason we become angry (in a sinful way) is because we cannot control something we desperately want to control. Therefore when we become angry in a particular situation, it is because we want to control that situation - and are not content to submit ourselves to God's sovereignty and providence. When we become angry with someone - it is because they are acting in a way that we cannot control. We are not content to submit ourselves to God in serving them - even if they do not act in a way that is consistent with how "WE" would control them if we could. Needless to say, I suddenly understood the core problem with much of my anger. I was a fool who wanted to control everything according to my will - rather than living according to God's will. I was not willing to thank God for all things and in all things. I found His providence annoying - at least to the way that I would have been God if I could be. Much conviction ensued - followed by repentance for thinking I was wiser than God. Time and space does not permit me to relate how often after that I was able, by submission and surrender to God's perfect wisdom and control of my providence, to hold back my temper and anger by the working of His Spirit.
What is interesting about this proverb is that we are told that the wise man "holds" his temper back. The word used for the holding back of our temper is the Hebrew word "shabach," which means to soothe or to still something. Here it is used of anger that rises up within us. The actual word for "temper" here is "ruach" which means spirit. We learn to hold back our spirit when it wants to react in anger. We should know from the rest of Scripture that more than one spirit can be expressed through us. When James and John wanted to call down fire on some who rejected Jesus - our Lord responded by rebuking the two brothers. He told them that they did not know what "spirit" they were of when they made that request. Peter, when he told Jesus He could never go to the cross, was called Satan - because that is whose spirit was expressed through Peter. The wise man therefore knows how to hold back the wrong kind of spirit from coming forth from him. When angry it is easy to not soothe and control what kind of spirit comes forth from us - but we still need to soothe our spirits and make sure that what comes forth from us is not the flesh, not the wrong demonicly inspired spirit. We need to have the spirit of God - who is patient, kind, and full of self-control - soothe our anger and keep us from reacting in rage or anger. A wise man knows this - and practices it when he senses anger begin to rise up within him.