I answered this on Yahoo Answers and I thought you might enjoy my thoughts.

“A friend recently introduced me to The Secret: Law of Attraction, a concept I found extremely interesting. Upon further research, I found that it is strongly linked with the new thought movement. Both of these concepts believe that everything in our lives is attracted to us via our thoughts, so illness comes from negative thoughts. How can this be applied to, for example, a 6-year-old boy with Duchenne Muscular Dystrophy, or a very ill baby, as they aren’t going to have negative thoughts enough to bring on such illness? I just don’t understand how this works, and when asking my friend, who is a complete believer in this, she didn’t know the answer.”

My Answer:
New thought is not a theory of everything.  People are born with certain propensities toward health, well-being, attitude etc.  You will find those who are attracted to New Thought are searching for meaning.  There are just some things we don’t understand.

Why a child is born with a life-threatening or debilitating illness is a mystery.  That being said, the child’s life is still being dramatically influenced by his or her thoughts and the thoughts of others.  An infant is positively influenced by the loving and secure feelings of those around it.

If the 6-year-old child, by the grace of God or some higher power, is able to step back and feel blessed for being alive as long as he or she has been, then a transformation will occur in the child’s experience.  Life will suddenly seem “better”.  Though nothing will have changed.  This might influence the child’s health condition in a positive way, and it might not.  It is still a mystery as to why some people miraculously heal while others don’t.  One thing is for certain.  If the child begins to feel gratitude for the time he or she has had here on Earth, then the experience of the illness will change.  The child will no longer feel like a victim and that will improve the child’s condition dramatically.  Maybe not physically, but emotionally.  There are many studies that demonstrate how a persons thoughts can improve their physical condition.  Many survivors of life-threatening illnesses attest to positive thoughts as an integral part of their healing process.

Rather than looking for evidence that proves New Thought to be inaccurate, spend some time investigating its’ accuracy in your own life.  Begin small.  Start by visualizing insignificant things that you want to manifest into your experience like a blue butterfly.  Visualize it and then notice how butterflies begin to show up everywhere in your life.  Don’t be attached to seeing an actual butterfly.  Be open to pictures, jewelry, etc.  When you see a butterfly, then pick something else.  Notice that what you focus on appears in your life.  Just keep visualizing small insignificant things until you appear.  This will build your belief that what you think about will show up.  With practice, you can get bigger and bigger.  Many people attest to this phenomenon but it must be experienced personally to really get it.