The Purpose of Health

Being as I spend a lot of time studing health issues, I've been thinking a lot about the purpose of health.  What's the point of being healthy?  On one level, it's a very simple answer: to be able to function and carry on.  Naturally, a part of this is selfish: a person wants to feel good, look good, be able to move efficiently, etc., just because it's natural to care about oneself and one's body.

Yet there are deeper motivations for health.  Here's a scenario: let's say a person achieves perfect health.  They are free of disease and all their systems are working.  But let's also say this person doesn't really do much with their life - they spend most of their time alone and don't feel a strong sense of purpose in life.  Would you predict this person will continue to exhibit good health?  I wouldn't.  Health cannot be the central goal in life - it is a means to other ends. 

I think motivation for health can come on two levels: for ourselves and for others.  It's great to set personal goals for weight, performance, etc., and then accomplish them.  It boosts self-esteem and provides a sense of control.  Yet I think the power of keeping ourselves healthy for our own sake only is limited.  Much greater motivational power lies in keeping up our health for the sake of others.  After all, how many people battle diseases for the sake of their family, their children? 

Staying healthy for others involves two reasons: 1) you can't interact with or care for someone if you're gone, and 2) you can't interact with or care for someone very well if your health is ailing.  We only have a limited number of years above ground - maintaining your health lets you get the most out of your time, and allows you to fully contribute to the lives of those around you.