The rationalists, following the example of Muhammad ibn Zakariya al-Razi, were led to this by the exaggeration of the Shi'a in their call for the Imams. Before him were the debates of Abu Hatim al-Razi with Abu Bakr al-Razi. These debates are published in the philosophical epistles collected by Professor Kraus. Among what Abu Hatim al-Razi mentioned at the beginning of the debates is his statement: "What transpired between me and the heretic was that he debated me on the matter of prophecy, saying: 'From where do you assert that God singled out some people for prophecy over others, favored them over people, and made them subservient to them and most in need of them? And from where do you permit the wise one to choose this for them, to confirm enmities among them, to magnify conflicts, and thereby to rule people?' He replied to him that the wise one did this out of mercy for people. For people, with their differing intellects, cannot do without those who guide and lead them, such as prophets, imams, and scholars, etc. . . . 'You see from this that there was a violent movement between the heretics who denied prophecy and the believers who believed in it. And to the credit of the Shi'a, they were believers who defended Islam externally against the Crusaders who attacked their lands, and internally, they repelled those who denied religion and rejected prophecy."