What is Spiritism?

42. Another, equally important point to consider is the fact that spirits are free; they communicate when they want, with whom they want and when they are able because they have their occupations to attend to. They are not at the beck and call of anyone, no matter who they are, and no one has the right to make them come against their will or make them reveal what they must keep silent about. Consequently, no one can say for certain that a particular spirit will come upon being evoked at a set time, or respond to this or that question. To say otherwise is to display one's complete ignorance about the most basic principles of Spiritism.
Only charlatanism hasfailsafe sources.