The knowledge of all things is possible - Leonardo da Vinci

In order to prove whether the spirit can speak or not, it is necessary in the first place to define what a voice is and how it is generated.

ليس هناك ما يسمى بالمعرفة الكبرى أو المعرفة الصغرى، بل هناك نوع واحد من المعرفة وهو ذلك النوع الذى يأتى عن طريق التجريب

You will never have a greater or lesser dominion than that over yourself...the height of a man's success is gauged by his self-mastery; the depth of his failure by his self-abandonment. ...And this law is the expression of eternal justice. He who cannot establish dominion over himself will have no dominion over others.