The practice of the companions is one of the institutions applicable in legal texts. It has been studied seriously and scientifically. Perhaps, it is due, mainly, to the same reason that jurists and experts of legal methodology differ in their opinions about it. The proponents maintain that it has numerous functions but opponents have found no reason to accept those functions. However, a group of scholars have adopted a middle approach accepting some functions and rejecting some others. The solution to this discrepancy depends on accurate understanding of the status of the companions and their practice. In order for a jurist to make use of it, he should arrive at certainty. To attain certainty, there are certain conditions to be fulfilled in order for one to get rid of illusion. The use of this institution is subservient to inferential methods. For this reason, it is not in consistent with the mathematical school but it is in consistent with the school of accumulation of speculations or the school of certainty.