This, however, is only accomplished by constant compromises which are seldom successfully carried out without a long national experience. Party must exist. It must be maintained as an essential condition of good government, but it must be subordinated to the public interests, and in the public interests it must be in many cases suspended. There are subjects which cannot be introduced without the gravest danger into the arena of party controversy. Indian politics are a conspicuous example, and, although foreign policy cannot be kept wholly outside it, the dangers connected with its party treatment are extremely great. Many measures of a different kind are conducted with the concurrence of the two front benches. A cordial union on large classes of questions between the heads of the rival parties is one of the first conditions of successful parliamentary government. The Opposition leader must have a voice in the conduct of business, on the questions that should be brought forward, and on the questions that it is for the public interest to keep back. He is the official leader of systematic, organised opposition to the Government, yet he is on a large number of questions their most powerful ally. He must frequently have confidential relations with them, and one of his most useful functions is to prevent sections of his party from endeavouring to snatch party advantages by courses which might endanger public interests. If the country is to be well governed there must be a large amount of continuity in its policy; certain conditions and principles of administration must be inflexibly maintained, and in great national emergencies all parties must unite.