Positive thinking can be defined by the goal of health and happiness. It concentrates at positive qualities such as inner peace, strength, love, joy and happiness. In this direction reseach the positive psychology. Positive thinking is a mental technique, that must practiced wisely. It should not be misused to repress feelings or problems. Positive thinking must used sensitively and healingly.
Wikipedia: Optimism is a mental attitude that interprets situations and events as being best (optimized). A common idiom used to illustrate optimism versus pessimism is a glass with water at the halfway point, where the optimist is said to see the glass as half full, but the pessimist sees the glass as half empty. Optimism may be linked to health. Optimists have been shown to live healthier lifestyles which may influence disease. For example, optimists smoke less, are more physically active, consume more fruit, vegetables and whole-grain bread, and consume more moderate amounts of alcohol. The relationship between optimism and health has also been studied with regards to physical symptoms, coping strategies and negative affect for those suffering from rheumatoid arthritis, asthma, and fibromyalgia. A meta-analysis has confirmed the assumption that optimism is related to psychological well-being: “Put simply, optimists emerge from difficult circumstances with less distress than do pessimists. (...) Optimists seem intent on facing problems head-on, taking active and constructive steps to solve their problems; pessimists are more likely to abandon their effort to attain their goals.”
The psychological learning theory 
The psychological learning theory suggests that positive thinking can be learned. An athlete trains for several weeks or months an external behavior. He carries a certain behavior, and after some time he masters it. Thoughts can be understood as the internal behavior of a person. When we consciously practice some time a positive mental behavior, then our mind accustoms to positive thinking. It automatically responds to certain external situations with positive thoughts.
Positive thoughts lead to positive feelings. And positive feelings lead to health and happiness. To train positive thoughts has a great gain. It gives us a happy and healthy life. Especially if we practice also regularly sports (yoga, walking), enough relaxation (enough breaks, enough sleep, daily meditating) and a healty diat (at least an apple a day).
How to learn positive thoughts? The learning method consists of four steps. First, we need a positive thought system that suits us like the philosophy of happiness. The philosophy of happiness teaches to make the happiness to the center of life. The essence of the philosophy of happiness are the five qualities of wisdom, peace, love, strength and joy. These five properties we practice every day.
The second step is systematically to train positive thoughts. The best way is to remember every morning on the five positive qualities. We create a positive plan of the day. We get up with a positive thought. We retain our positive vision during the day. And at night we think about the day and what we can do better the next day. We feel our negative emotions (fear, anger, grief, addiction). What negative thought is associated with it? What positive thought helps us to overcome it? Which thought brings us into a positive attitude towards life? Helpful positive phrases are, "I'm a winner. I reach my goals. Wisdom is to organize my life so that I can live healthy and happy. "
The third step is to observe consistently our thoughts throughout the day, and to stop all negative thoughts. If we recognize a negative thought, we push him away immediately. We consider what positive thought is helpfull right now. We develop a positive thought and set it in place of the negative thought. If we make this at the long term, our negative thoughts are becoming less and our positive thoughts grow more and more. Nils was able to overcome his depression by this technique.
The constant observation of thought is the essence of positive thinking. Often we overcome our negative thoughts already through the constant observation of our mind. We are aware of our negative thoughts and that already deprives them their power. Sometimes we have to intervene forcefully. And just at the beginning of our mental work we should be relatively strict with our thoughts. If our inner children are educated good, we can give them a little more freedom.
The fourth step is the stabilization of positive thinking. It is not easy all day to control our negative thoughts. We need strong helpers to keep us on our long-term path of inner happiness. Such helpers are the daily spiritual reading in a book, the daily oracle reading, the daily meditation, walking and a group of positive thinking people. Very good it is to distribute some caregivers throughout the day. We create our system of daily happiness exercises. We're putting so many exercises for us in right intervals in the day that we keep ourselves constantly on the path of the positive. We stay with perseverance on our way of wisdom and happiness. If we fall off the path once, we stand up again next day. In particularly difficult situations helps the constant change of lying (hearing meditation music), reading (praying, chanting), sports (yoga, walking) and work (doing good to others). We are practicing it for so long until our negative emotions have calmed down und we are positive again.
Overcome Pain and Grief 
The supreme principle of conduct in suffering situations is outwardly behaving properly and at the same time managing the thoughts and feelings as well as possible. Is the difficult situation outside gone, we can heal our emotional wounds. At certain points of the problem we got inner tensions. This tensions must be resolved again when the external stress situation is over. When we don´t heal ourself after stress situations, they remain permanently in our mind. In the long term they affect our mental well-being. They lead to neurotic behavior and can cause physical illnesses.
If a problem affects you emotionally, it is good to do a helpful ritual. Think first about the problem. Thinking leads to constructive engagement with the problem. You realize that you can do something. You are not a helpless victim. You can live as a winner. You can solve the problem in any way. What is your helpful idea about your problem? “My idea is …”
Read a few pages in a spiritual book. Think about which book you need now. A spiritual book has a positive energy field. If we spend some time in this energy field, we get a positive spirit. Which book will strengthen your positive energy? Read it! After reading, take a walk for an hour or dance 20 minutes as you like. Move all the rage and excitement out of your body. Think a Mantra (a positive sentence) and do a meditation (stop your thinking five minutes). Then think about your problem. Usually you will come to rest mentally in half an hour. Half an hour then go just you like. Then you’ll see things clearly. You will be able to have positive ideas. Make after the walk some yoga exercises (creative hatha yoga) and a long meditation in sitting (meditation with the inner voice) or lying down. Hook up a nice music and remain lying down for so long, until your mind completely is at rest. Arise then again, eat something nice and think about what you need now. Give it yourself. Often it is very helpful to do something creative. We can paint, write, make music and express our feelings on our personal way. We can do something good for our fellow human beings and thus bring us into the energy of love. What is your way of love now?
If the problem is very big, you can do several rounds of reading, walking, doing good, enjoying and meditating. Usually you get then to the point, where peace arises within you. Be very gentle with you and heal emotionally more and more. If a problem can not be solved in one day, stop after a while your thinking about the problem. Forbid you every further reflection. Avoid harmful rumination, which leads to nothing and only reinforces the internal stress. For large problems, you can take every day a certain time for problem handling.
To solve emotinal problems is a creative process. You must feel exactly what you need now. What is currently the best way to solve your problem, to find inner peace and positivity? People are different and require different strategies. It is important to avoid self-defeating behaviors, such as tablets, smoke, drink, drugs, alcohol or eating too many sweets. It is better to manage the problem with the techniques of inner happiness. Then we grow spiritually on our problems. We grow inwardly on the problems of life until we will find ever lasting happiness.
Happy in Five Minutes 
In every life there is pain, loss, illness, loneliness and death. We have no claim to a long life still to be spared by fate. What is your pain today?
1. The problem: Describe briefly your situation and your problem. How exactly is your situation? What is the problem? Where is the center of the problem?
2. The Emotions: What are the feelings it in you? Fear, anger, addiction / desire, grief. What feeling is strongest? Where is the feeling sitting in your body?
3. The thoughts: What thoughts are connected with your feelings? Why are you sad, anxious, angry or longing? Count all your stressful thoughts down. (My thoughts are ...)
4. Thinking: What triggers your problem? What is the way out of your problem? What brings you to love, success, fulfillment, satisfaction? Think about your problem for so long, until you find a solution. Think about different solutions. Collect all the information you need.
5. Implementation: Follow your positive thoughts. Fulfil your positive life plan. Avoid meaningless brooding. Now is the time to realize powerful. Go your way to victory. "My positive sentence is ...."
Enlightenment and positive thinking 
According to the Buddhist master Tsongkhapa enlightenment is created by the wise combination of positive thinking and meditation. Buddha used the term of right thinking. The combination of mind work and meditation is the basis of the eightfold buddhist path and the eightfold yoga path (Patanjali).
See also 
- Happiness research
- Philosophy of Happiness
- Everyone needs a spiritual centering
- The Five Principles of Health
- Happiness oracle (Tarot)
- A World of Peace, Love and Happiness
- Encyclopedia Britannica learning theory
- How to Be Positive
- Reduce stress by eliminating negative self-talk
- Positive Thinking Your Key to Success
- The Power of Positive Thinking