You are probably saying to yourself by now：“This man Carnegie is proselytising for Christian Science.”No.You are wrong.I am not a Christian Scientist.But the longer I live，the more deeply I am convinced of the tremendous power of thought.As a result of thirty-five years spent in teaching adults，I know men and women can banish worry，fear，and various kind of illness，and can transform their lives by changing their thoughts.I know！I know！！I know！！！I have seen such incredible transformations performed hundreds of times.I have seen them so often that I no longer wonder at them.
For example，one of these transformations happened to one of my students，Frank J.Whaley，of 1469West Idaho Street，Saint Paul，Minnesota.He had a nervous breakdown.What brought it on？Worry.Frank Whaley tells me：
“I worried about everything：I worried because I was too thin；because I thought I was losing my hair；because I feared I would never make enough money to get married；because I felt I would never make a good father；because I feared I was losing the girl I wanted to marry；because I felt I was not living a good life.I worried about the impression I was making on other people.I worried because I thought I had stomach ulcers.I could no longer work；I gave up my job.I built up tension inside me until I was like a boiler without a safety valve.The pressure got so unbearable that something had to give—and it did.If you have never had a nervous breakdown，pray God that you never do，for no pain of the body can exceed the excruciating pain of an agonised mind.
“My breakdown was so severe that I couldn’t talk even to my own family.I had no control over my thoughts.I was filled with fear.I would jump at the slightest noise.I avoided everybody.I would break out crying for no apparent reason at all.
“Every day was one of agony.I felt that I was deserted by everybody—even God.I was tempted to jump into the river and end it all.
“I decided instead to take a trip to Florida，hoping that a change of scene would help me.As I stepped on the train，myfather handed me a letter and told me not to open it until I reached Florida.I landed in Florida during the height of the tourist season.Since I couldn’t get in a hotel，I rented a sleeping room in a garage.I tried to get a job on a tramp freighter out of Miami，but had no luck.So I spent my time at the beach.I was more wretched in Florida than I had been at home；so I opened the envelope to see what Dad had written.His note said：‘son，you are 1，500miles from home，and you don’t feel any different，do you？I knew you wouldn’t，because you took with you the one thing that is the cause of all your trouble，that is，yourself.There is nothing wrong with either your body or your mind.It is not the situations you have met that have thrown you；it is what you think of these situations.“As a man thinketh in his heart，so is he.”When you realise that，son，come home，for you will be cured.’
“Dad’s letter made me angry.I was looking for sympathy，not instruction.I was so mad that I decided then and there that I would never go home.That night as I was walking down one of the side streets of Miami，I came to a church where services were going on.Having no place to go，I drifted in and listened to a sermon on the text：‘He who conquers his spirit is mightier than he who taketh a city.’Sitting in the sanctity of the house of God and hearing the same thoughts that my Dad had written in his letter—all this swept the accumulated litter out of my brain.I was able to think clearly and sensibly for the first time in my life.I realised what a fool I had been.I was shocked to see myself in my true light：here I was，wanting to change the whole world and everyone in it—when the only thing that needed changing was the focus of the lens of the camera which was my mind.
“The next morning I packed and started home.A week later I was back on the job.Four months later I married the girl Ihad been afraid of losing.We now have a happy family of five children.God has been good to me both materially and mentally.At the time of the breakdown I was a night foreman of a small department handling eighteen people.I am now superintendent of carton manufacture in charge of over four hundred and fifty people.Life is much fuller and friendlier.I believe I appreciate the true values of life now.When moments of uneasiness try to creep in （as they will in everyone’s life）I tell myself to get that camera back in focus，and everything is O.K.
“I can honestly say that I am glad I had the breakdown，because I found out the hard way what power our thoughts can have over our mind and our body.Now I can make my thoughts work for me instead of against me.I can see now that Dad was right when he said it wasn’t outward situations that had caused all my suffering，but what I thought of those situations.And as soon as I realised that，I was cured-and stayed cured.”
Such was the experience of Frank J.Whaley.I am deeply convinced that our peace of mind and the joy we get out of living depends not on where we are，or what we have，or who we are，but solely upon our mental attitude.Outward conditions have very little to do with it.
Or take the case of Robert Falcon Scott and his companions—the first Englishman ever to reach the South Pole.Their return trip was probably the cruelest journey ever undertaken by man.Their food was gone—and so was their fuel.They could no longer march because a howling blizzard roared down over the rim of the earth for eleven days and nights—a wind so fierce and sharp that it cut ridges in the polar ice.Scott and his companions knew they were going to die；and they had brought a quantity of opium along for just such an emergency.A big dose of opium，and they could all lie down to pleasant dreams，never to wake again.Butthey ignored the drug，and died “singing ringing songs of cheer”.We know they did because of a farewell letter found with their frozen bodies by a searching party，eight months later.