This Society of Friends increased greatly in Persia, and up to the present time their societies exist. Many books and epistles were written by their leaders. When they assemble in their meeting- house they sit silently and contemplate; their leader opens with a certain proposition, and says to the assembly `You must meditate on this problem'. Then, freeing their minds from everything else, they sit and reflect, and before long the answer is revealed to them. Many abstruse divine questions are solved by this illumination.