The Book of Knowledge: being a translation with notes of the Kitāb al-‘ilm of al-Ghazzālī’s Iḥya’ ‘ulūm al-dīn, translated by Nabih Amin Faris, Islamic Book Service, New Delhi, 19621 2 3

Al-Ghazali, Iḥyā′ ‘Ulūm al-Dīn (The Revival of the Religious Sciences), Book 1: The Book of Knowledge

Section V, Seventh Duty of Students, pp. 129-130:

The seventh duty is that no one should address himself to one branch of knowledge before he has already mastered the branch which precedes it because science is of necessity so arranged that one branch prepares for another and one branch leads to another. Only the person who would observe this order would succeed. God said, “Those to whom We have given the Book, they read it as it ought to be read.”4 In other words they do not leave a single branch of knowledge until they have mastered it in theory and in practice. Furthermore, in every branch of knowledge which the student may pursue, his aim should be the one above. Nor should he ever declare a certain science useless because its protagonists disagree among themselves, or because of the error of one or more among them, or because with their actions they violate the ordinances of their own science. Thus you find some who have relinquished the philosophical and theological sciences excusing themselves on the grounds that if these sciences had any truth in them they would have been comprehended by their protagonists. (These fallacies have been exposed in the Mi‘yar al-Ilm). Others believe that the medical science is false because of an error they have seen committed by a physician. Another group believes in the authenticity of astrology because a single prediction involving a certain person turned out right while others disbelieve it because in another case the prediction was faulty. All are wrong, however. Each case should be determined separately, as not every branch of knowledge can be independently mastered by every person. For this reason ʿAlī said, “Accept no truth because of the men who hold it but first find the truth and thou shalt know who are its real protagonists.”

Section V, Fourth Duty of Teachers, pp. 141-142:

The fourth duty which is one of the finer points of the profession of teaching is that the teacher, in dissuading the student from his evil ways, should do so by suggestion rather than openly, and with sympathy rather than with odious upbraiding. Open dissuasion destroys the veil of awe, invites defiance, and encourages stubbornness. The Prophet, who is the guide of every teacher, said in this connexion, “If men had been forbidden to make porridge of camels’ dung, they would have done it, saying that they would not have been forbidden to do it unless there had been some good in it.”5 The same principle is brought out in the story of Adam and Eve and the prohibition imposed upon them. This story has not been related as a night entertainment but as an example and a reminder. Such allusions and suggestions invite men of noble souls and discerning minds to attempt to elicit their import, and the pleasure of grasping their meaning results in a greater desire on the part of man for learning in order to show that such things are not beyond the capacity of his intellect.

Section V, Fourth Duty of Teachers, Arabic text, Shamela.ws:

الوظيفة الرابعة وهي من دقائق صناعة التعليم أن يزجر المتعلم عن سوء الأخلاق بطريق التعريض ما أمكن ولا يصرح وبطريق الرحمة لا بطريق التوبيخ فإن التصريح يهتك حجاب الهيئة ويورث الجرأة على الهجوم بالخلاف ويهيج الحرص على الإصرار إذ قال صلى الله عليه وسلم وهو مرشد كل معلم لو منع الناس عن فت البعر لفتوه وقالوا ما نهينا عنه إلا وفيه شيء وينبهك على هذا قصة آدم وحواء عليهما السلام وما نهيا عنه فما ذكرت القصة معك لتكون سمراً بل لتتنبه بها على سبيل العبرة ولأن التعريض أيضاً يميل النفوس الفاضلة والأذهان الذكية إلى استنباط معانيه فيفيد فرح التفطن لمعناه رغبة في العلم به ليعلم أن ذلك مما لا يعزب عن فطنته

Section VI, p. 157:

Among the learned are those who would guard their knowledge and dislike the idea of sharing it with others -these will occupy the first depth in Hell. There are others who are in the habit of regarding their knowledge as equivalent to power and position; and if they are ever contradicted or slighted they become infuriated - these will occupy the second depth in Hell. Others confine their knowledge to the circles of nobility and wealth and deem the poor classes unworthy of it - these will occupy the third depth in Hell. Others appoint themselves judges and hand down faulty opinions - these will occupy the fourth depth in Hell. Other learned men employ in their discourses Jewish and Christian arguments in order to make their erudition seem great - these will occupy the fifth depth in Hell. Others regard their knowledge as something virtuous and honourable and continually dwell on it before men - these will occupy the sixth depth in Hell. And finally there are the learned men who are the victims of vanity and conceit. Whenever they preach they upbraid, and whenever they are admonished they show resentment - these will occupy the seventh depth in Hell. Therefore O brother, observe silence, for through it you will overcome Satan. Do not laugh without cause and do not move without direction.

  1. Ghazali.org: Iḥyāʾ ʿulūm al-dīn (Revival of the Religious Sciences) 

  2. Archive.org 

  3. Arabic text at Shamela.ws 

  4. Surah 2, Verse 121 (Sahih International translation): “Those to whom We have given the Book recite it with its true recital. They [are the ones who] believe in it. And whoever disbelieves in it - it is they who are the losers.” Quranic Arabic Corpus 

  5. Shamela.ws, Murtada al-Zabidi, Itḥāf al-sadāh al-muttaqīn