But though the speculative element in the school of Malik, apart from its local and historical environment, which gave it unifying weight, was essentially the same as in the school of Abu Hanifa, yet it is true that at al-Madina it played a less important part. Malik used tradition more copiously and took refuge in opinion less frequently. Without opinion, he could not have built his system; but for him it was not so much a primary principle as a means of escape. Yet one principle of great freedom he did derive from it and lay down with clearness; it is the conception of the public advantage (_istislah_). When a rule would work general injury it is to be set aside even in the teeth of a valid analogy. This, it will be seen, is nearly the same as the preference of Abu Hanifa. The technical term _istislah_, chosen by Malik to express his idea, was probably intended to distinguish it from that of Abu Hanifa, and also to suggest in the public advantage (_maslaha_) a more valid basis than the mere preference of the legist. [Sidenote: THE DOCTRINE OF AGREEMENT] Another conception which Malik and his school developed into greater exactitude and force was that of the agreement (_ijma_). It will be remembered that from the death of Muhammad all the surviving Companions resident in al-Madina formed a kind of consultive council to aid the Khalifa with their store of tradition and experience. Their agreement on any point was final; it was the voice of the Church. This doctrine of the infallibility of the body of the believers developed in Islam until at its widest it was practically the same as the canon of catholic truth formulated by Vincent of Lerins, _Quod ubique, quod semper, quod ab omnibus_. But Malik, according to the usual view, had no intention of granting any such deciding power to the outside world. The world for him was al-Madina and the agreement of al-Madina established catholic verity. Yet there are narratives which suggest that he approved the agreement and local usage of al-Madina for al-Madina because they suited al-Madina. Other places might also have their local usages which suited them better.