From the introduction:
Psionics are a supernatural force, but, unlike magic, it does not come from the world. It does not come from a deity. It does not come from other planes of existance. It comes from within. Generated by all living creatures, day in, day out, it is a silent force, a power. A power which can be harnessed by those with the Will, by those who know the Way. Come. You know the Way.