A thetan is the Scientology word for the soul or human spirit. The reason that there is a new separate word for this is because in Scientology certain laws about the spirit have been isolated and this required a new term to describe the new understanding.
Chief among these discoveries is the fact that a person does not have a spirit, rather he is a spirit. So instead of getting mixed up with the old belief that one merely has a spirit, we have simply adopted the word thetan and thus there is no chance of mistaking what we are talking about.
You may have heard people say “when I die my soul will go to heaven.” This statement indicates that you are something separate and distinct to the spirit. However it has been proven conclusively in Scientology that one is the spirit (thetan) and he has a body and has a mind.
There is a test of this that one can make that can see that he is a spirit and as a result also answer the eternal question of “does Man have a soul?” It is done in a few steps. First, you close your eyes and think of a cat. You should actually get the picture of the cat, with its colors and details.
The next step is to ask yourself, “who looked at the cat?” Well, it obviously was not your body, because there was not a physical cat there between your eyes and your eye lids. So it was you, the thetan, looking at that picture of the cat. This shows you two of the three Parts of Man. The spirit (thetan) and the body.
Then there is mind. The mind is a collection of mental image pictures that a person uses to think with, make conclusions and solve problems. In the example above, the image of the cat is part of the mind. All of one’s mental image pictures together would be the mind, which is the third and last of the Parts of Man.
However, the most important of these three parts is, quite obviously, the thetan. The word thetan was taken from the Greek letter theta (θ) to which an “n” is added that means “to the Nth power” and is used to signify that the spirit is unlimited and has infinite potential (the Greek letter theta means spirit). A thetan is the creator of things. It is a person, a being, who creates all of the art that you see around today. Bodies do not create such things as music, paintings, sculptures or buildings. It takes a person to compose a song, to paint a masterpiece, to sculpt a statue or to plan a building. This is the spiritual nature of Man as a creator of things.
The spiritual aspect of life is seen in Scientology to be one of eight different parts of life. These are called the Eight Dynamics. A thorough understanding and knowledge of these eight components of life and of one’s spiritual nature can be found in the free Scientology online course The Dynamics of Existence, and with this knowledge can come a more profound and fulfilling existence.