disputeisforbidden

It is true that debate and discussion is the key to the solution of difficulties. However, this is so only if discussion is pursued on the basis of search for truth and reality and discovery of facts. And in case one or both of the two parties commence dispute and contention to assert superiority over the other and to support their personal points of view the result will be nothing except darkness of heart, concealment of truth and establishment of discord and enmity.

Islam condemns dispute and controversy in material matters as well as in scientific discussions and considers it to be the cause of discord and enmity.

The Commander of the Faithful Imam Ali (AS) says:
"Refrain from dispute and controversy because it offends two brethren in-faith and gives birth to mutual enmity."

Imam al Sadiq (AS) says:
"Refrain from dispute and controversy in your discourse, because dispute gives birth to anger and divulge's one's secrets."

"One who disputes with others loses manliness"

And Imam Ali (AS) says:
"Whoever loves self respect abandons dispute."

And again Imam al Sadiq (AS) says:
"Refrain from dispute and controversy, because dispute occupies one's intellect with itself and places discord and enmity in its place and gives birth to jealousy and hatred."

Islam not only prohibits unjustified dispute and controversy but also forbids a truthful person from indulging in such an act.

Imam Ali (AS) says:
"A person cannot attain perfection of the reality of his faith except when he abandons dispute, even though he may be a truthful person."

And the holy Prophet (AS) says:
"I enjoy authority over a house above Paradise, another house within Paradise and still another house in the garden of Paradise. They are for one who abandons dispute and controversy even though he may be right."

For this very reason Islam declares that same actions like Aitikaf (seclusion) and Hajj are invalidated by dispute. Imam al Sadiq (AS) interprets it in this way that you might be saying "by Allah, yes" and "by Allah, No", which are the lowest stages of strife and controversy.