Excerpt From:

Imam Al-Ghazali's Ihya Ulum-id-din
The Book of Knowledge, Book 1 Section iv page 52
Translated by Maulana Fazlul Karim,

Harms of the science of polemics and evils of debates and disputations

"Know, O dear readers, that after the Prophet (, the rightly-guided caliphs were the leaders of the learned in the science of God. They were the eyes of knowledge and were experienced in legal decisions. They did not take the help of jurisprudents except in cases where consultation was necessary. They decided on the strength of Ijtihad and their decisions were recorded in their lives.After their death, the Caliphate went to those who were not so experienced in legal matters and administrative affairs. They were compelled to seek the aid of jurisprudents. At that time, a band of Tabeyin (successors of the companions) were alive and they persisted in following strictly the injunctions of religion. Whenever the Caliphs called them, they fled. But some learned men used to mix with the Caliphs and consequently became humiliated. Therefore there were differences of opinions among the learned men and there grew different Mazhabs or sects as a result. There were argumentations and disputations over the intricate questions of religion. They composed also many works on these subjects. This induced the people to take to controversies and disputations.

" There are eight conditions of debate

(1) The first condition is that where debate is for search of truth is one of farze kefayah duties. one who has not already fulfilled his part in duities of farze Ain n), should not engage himself in the debates, even for searching truth.
(2) The second condition is that one should not consider debates more important than Fard Kifayah duties. He commits sin who does other works, leaving aside a more important Farze Kifayah duty. He is like a man who does not give water to drink to people who are thirsty and facing death, even though he has got the power to do so, because he remains busy in giving lessons of cupping. Once the Prophet was asked: "When will the people give up enjoining good and forbidding evil?" He said: "When flattery will grow in good people among you, kingdom will go to the meanest of you, and theology to those who will be corrupt."
(3) The third condition which justifies debate is that the debater should have the ability and give decision on one's own responsibility. Without referring to the opinion of Imam Abu Hanifah or any other Imams. He who has not the ability of independent interpretation should not express his opinion but should refer to an Imam.
(4) The fourth conditions which justifies debate is that the subject for decision should be about actual cases that crop up. for example, the question of inheritance and not about future cases. The companions also held consultations as questions arose or were likely to arise in order to arrive at truth.
(5) The fifth condition debate should be held in private, in preference to open meetings in presence of noted people and in grandeur because privacy is more suitable for clear thinking and to examine what is right and what is wrong.
(6) The sixth condition is that the debater should like truth in the same spirit as seeking a lost cherished object. He should not mind whether the truth is found by oneself, or by him or his adversary. When Hazrat Omar was once giving sermon, a woman pointed out to him his mistake, to which he submitted. At another time Hazrat Ali was asked a question by a man, to which he replied. When the man pointed out his mistake, hei admitted it.
(7) The seventh condition is that the debater should not prevent one's adversary from giving up one argument in favour of another and one illustration in favour of anather.
(8) The eighth condition is that the debate should be held with such a person, from whom benefit is derived and who is learned.

From these eight conditions, you will be able to distinguish those who debate for the sake of God , and those who debate for other purposes. 

Note: We have kept this excerpt as close as possible to the books, however we could have unknowingly made some error.

www.kitaabun.com