A "thetan is an immortal spiritual being; the human soul."
"The being who is the individual and who handles and lives in the body."
"A thetan is not a thing, a thetan is the creator of things."
In Scientology, Operating Thetan (OT) is a spiritual state above Clear.
It is defined as "knowing and willing cause over life, thought, matter,
energy, space and time (MEST)."
However, Scientology considers that its understanding of the thetan
distinguishes it from other religious traditions,
especially Judaism and Christianity, in three important ways.
First, while many religions fuse the concept of the body and the soul,
the thetan (spirit) is separate and independent.
Second, unlike the three great world monotheisms,
Scientologists believe in past lives and that the thetan has lived through many,
perhaps thousands of lifetimes.
Third, contrary to Christian concepts of original sin,
Scientology holds to the intrinsic goodness of a being and
believes that the spiritual essence has lost touch with its nature.
"The spirit, then, is not a thing," Hubbard writes.
"It is the creator of things."