It is known, that the ijma’ is one of the important Principles in the theology of the ortodoxy islam (Ahla’l-Sunnah). The ijma is important too, that the tradition goes ahead through it. On the other side it is obstacle to the ijtihad', which means the individual thinking (re’y). The qiyas is the instrument of ijma’ and opposite to the re’y ijtihad. We have shown, that the supporters of two doctrines have struggled in the history of Islam