In a general estimate of Mohammedanism it should not be forgotten what Islam has done for the cause of humanity and more particularly the share it had in the development of science and art in Europe. Broadly speaking, the Mohammedans may be said to have been the teachers of barbarous Europe from the ninth to the thirteenth century. It is from the days of the Abbasside rulers that the real renaissance of the Greek spirit and Greek culture is to be dated.