In the recent case, Great Western Ry. Co. v. Owners of S.S. Mostyn, Viscount Dunedin said: ‘Now, when any tribunal is bound by the judgment of another Court, either superior or co-ordinate, it is, of course, bound by the judgment itself. And if from the opinions delivered it is clear—as is the case in most instances—what the ratio decidendi was which led to the judgment, then that ratio decidendi is also binding. But if it is not clear, then I do not think it is part of the tribunal's duty to spell out with great difficulty a ratio decidendi in order to be bound by it.’ In other words, not only the judgment itself, but also the grounds on which the judgment was reached, are binding. This proposition must, of course, be understood to include the further rule that only those reasons are binding which were material to the decision of the point at issue. If they were material they constitute a precedent; if they were not material they are merely obiter dicta.