Pope Benedict XVI says science has narrowed humanity's understanding of the origins of life and that the theory of evolution can neither be proven or dismissed.
The pope's extended views on evolution are appearing in print for the first time as part of a newly published German book called Creation and Evolution.
He writes that evolution can never be known for sure because it is impossible to conduct controlled laboratory experiments into the theory.
But Benedict does not give a 100 percent endorsement of creationism or intelligent design, saying the debate must be philosophical and go beyond science.
Advocates of intelligent design say life on Earth is too complex to have evolved randomly and must be the product of a higher power.
Some information for this report was provided by AP and Reuters.