Temperance!

Temperance is the quality of moderation in actions, thoughts, or feelings.  

The way I understand temperance is, it is not to have excessive emotions, like for instance when someone is experiencing a difficult time in life, having deep thoughts about it will only have a negative outcome. 

Consider the case of when you have a problem and keep thinking about it and giving it so much importance. Those thoughts may cause you to harm yourself. 

It can also be explained by having so much costume of alcohol or over-exercising or non-stop office work and this results to a negative approach to your body and brain, which results in poor judgment, inability to think, loss of appetite, and fatigue. 

To sum up what I can say is that if you really appreciate temperance, always remember to incorporate moderation into your life and lifestyle, and you'll be just fine.