I found this on Fallible Blogma.
I want to add a note.
One of the things we were reminded of during the pontificate of Bl. John Paul II was that we are our bodies. His “theology of the body” served to remind us that we are both soul and body, together. The body component we have as human beings is not something external or foreign to who we are as images of God.
What flows from this is that we are not free simply to treat even our own bodies as if they were possessions, something we own, like a car we ride in, a meat machine that hauls our souls around.
If we are not really our bodies, if our bodies are things we can treat any way it pleaseth us to treat them, abuse or drug or harm or kill or use for illicit pleasures, because – after all – its mine and I can use it as I want, then… someone else can abuse your body or drug it or harm it or kill it or use it for illicit pleasures because – after all – its just a object to be used.
We are not free to use our bodies as objects. Our bodies pertain to persons made in God’s image. Just as you are not free to use as an object another person (the free subject of their own actions) you are not permitted to harm yourself. In harming yourself you are harming an image of God, which – indeed who – should be treated with dignity.