THE MUQADDIMAH: An Introduction to History

by Ibn Khaldun

However, if the soul is infected with partisanship for a particular opinion or sect, it accepts without a moment's hesitation the information that is agreeable to it. Prejudice and partisanship obscure the critical faculty and preclude critical investigation.

Muhammad SAW said: "Every infant is born in the natural state. It is his parents who make him a Jew or a Christian or a Magian."