This research tackles important humanitarian issues, both old and new, dealt with by Al-Jahiz in his books and letters. The most important of which is the issue of intellectual freedom, mildness, and moderation. In the process of dealing with these matters, it became quite clear how Al- Jahiz was a humanitarian who persistently tried to find common ground and harmony between people as well as his continuous call not to turn variety and difference into conflict. And so, Al-Jahiz became quite the advocate of intellectual freedom of his time, dismissing all that restrains him, in different venues of life, and believing in the importance of different opinions. Consequently, he established a culture on civilized conversation and rejected all kinds of fanaticism, extremism, sternness, and accusations of infidelity. The research also attempts to delve deep down into Al-Jahiz’s intellect in the issues he tackled. It also tries to arrive at a reading of these issues in his texts. However, the research does not link Al-Jahiz’s intellect with the historical background or with the Mu’tazilah creed that made him glorify the mind making it his authority in every matter. Finally, the research attributes Al-Jahiz’s intellect to his rare literary genius that made him capable of approximating every creed to different kinds of minds.