I've been thinking about anger (because I've been thinking about love, but I'll come to that later...)
It seems to me that it is an emotion that needs expression. If it is suppressed, it sinks down to become resentment (literally - 're-sentiment' as in it will resurface to poison future relationships). Yet if it is expressed in an uncontrolled manner, it clearly has destructive or violent potential.
So how does one express genuine anger, not supressing it, yet not losing one's self-control.
I think it's impossible without the Holy Spirit (indeed self-control is the fruit of the Spirit), which would lead me to conclude that natural man cannot have healthy anger - to some extent, it will be either suppressed or violent.
Nevertheless, I believe all human emotions are relations (though sometimes distant relations) of love. Now there's a thought...
"Love is a feeling to be learned.
It is anxiety and contentment.
It is deep yearning and hostility.
It is pleasure and it is pain.
There is not one without the other.
Happiness is only a part of love.
Suffering belongs to love also.
This is the mystery of love,
its beauty and its burden." - Walter Trobisch