Islam is a firm supporter of logic, rational argument and freedom of thought. Imposition of ideas or beliefs, or the stifling of voices does not exist in Islam.
"No compulsion is there in religion, rectitude has become clear from error". (II:256)
In Islam, investigation of the foundations of beliefs is a duty for every individual, and it is an obligation for everyone not to accept anything without proof, and if some commands and precepts are obligatory and must be accepted without why and wherefore, it is because they are from the source of revelation which cannot be in error, and because they have been stated through the Prophet and the pure Imams. Islam censures those who blindly follow the beliefs of their fathers and ancestors, and commends self-investigation and deep examination. It rejects feeble-mindedness and vain speculation, and urges only to the persual of knowledge and certainty.
"and pursue not that thou hast no knowledge of; the hearing, the sight, the heart-all of these shall be questioned of". (XVII:36)
Islam grants its opponents the right to set forth their queries in reasonable discussion and to enumerate their proofs and listen to the answers.
"Say: `Produce your proof, if you speak truly." (II:111)
This was the reason that many Jews, Christians and those from other groups who took a stand against Islam, came to the Prophet or the pure Imams, and sat down and discussed their religious ideas.
source : http://www.maaref-foundation.com
