Al-Ghazali on the Lawful and the Unlawful : Book XIV of the Revival of the Religious Sciences (Ghazali Series) By Abu Hamid Al-Ghazali Al-Ghazali on the Lawful and the Unlawful : Book XIV of the Revival of the Religious Sciences (Ghazali Series) By Abu Hamid Al-Ghazali ISBN: 9781911141365 The Book of the Lawful & the Unlawful is the 14th chapter of The Revival of the Religious Sciences, which is widely considered as the greatest work of Islamic spirituality.