In other words...

In other words, foundations of happiness answer these questions: what is happiness? What is the difference between happiness and pleasure? What things cause happiness? Is it possible to reach happiness in this world? It is also meant by the combination "religious, philosophical and psychological foundations of happiness" in this book those answers that religions, (e.g. Islam in this research), philosophers and psychologists give to these questions.

Divine religions can have a philosophical origin. Therefore, many philosophical reasons can be put forward for the interpretation and justification of religious problems. Thus, there is a very close relationship between philosophy and religion, and then one might expect many similarities between philosophy and religion. Since these two, in turn, are based on thinking and cognition, it is quite reasonable that their teachings be consistent with scientific and empirical researches.

That is the reason why the main purpose of this research was the extraction of the philosophical and religious foundations of one of the most important philosophical-religious and psychological subjects; i.e. happiness.

Although "psychology" can be considered as a subset of philosophy, but since it is considered today as a separate and independent discipline, happiness can also be considered as a psychological topic, and many researches have been done regarding happiness in psychology; therefore, the main goal of this research is to extract the philosophers, psychologists and religion's (Islam) view of happiness.

Much emphasis is placed on inferring the shared philosophical, religious and psychological foundations. Non-Muslim and non-Iranian, and Muslim and Iranian, ancient or modern philosophers, were chosen who had some views of happiness and their views and character are reason or proof or all of the worldlings.

The major purpose of doing this was to reach a shared and common model and frame for happiness, or those things that can cause people to reach happiness, which is acceptable for various people of the world today, especially when these philosophical and religious views are compared with the most recent researches.…