Shams al-ma'arif (The Illumination of Knowledge).Author:- al-Buni AhmmadVolume Two : 138 Folios.430 Years old.

This is not to say that the spirit must be believed in as a matter of faith. Unfortunately for the skeptics, denial of the existence of the spirit grows more untenable with every major advance in biology. Each new examination of the body, every revelation about the brain, has (as shown below) fortified the conclusion that there must be, somehow, a spirit beyond the flesh. The body has been demonstrated to be highly complex yet ultimately mechanistic. Our nerves react to changes in polarity, and these are in tum regulated by chemicals. From basic bodily functions to the highest aspirations of the intellect, it is demonstrated time and again that the body is a masterpiece of carbon-based machinery. Every form of activity, barring none, has an observable and demonstrable basis in physical structures. The brain may be mysterious, but scientists are fully confident that everything we think, feel, and know are contained and processed in its millions of cells and their reactions to purely material chemicals.