VUB Crosstalks and Moussem set up a lecture series on critical thinking within Islam. In their ideas about Islamic civilisation both Muslim extremists and Islamophobes go back to an originally 'pure' Islam, which was supposedly born 1400 years ago, but in reality did not really exist. Islam was never one block, one movement. On the contrary, it has always been a very diverse culture, strengthened by acculturation and by coming in contact with the Greek, Persian, Indian, African culture etc. A history that is also full of dissidence, heresy and rebellion. These sects and alternative theological currents are at the root of a fascinating culture of debate. Philosophers from the golden age of Islam such as Al Farabi, Averroës, Avicenna, Abu Al Alaa Al Ma'ari Abu Bakr Al Razi, Omar Khayyam, Abu Hayyan Al Tawhidi... are founders of a culture based on reason and science. In today's complex world, attention to these forgotten thinkers is more than necessary. In this context, we present a series of online lectures and publish a new text by the speaker that relates to the theme.