The functions of a minister despatched on a mission to a foreign country fall into two principal categories: the first to conduct the business of his master, and the second to discover the business of others. The first of these concerns the prince or his ministers of state, or at all events those deputies to whom are entrusted the examination of his proposals. In all these different kinds of negotiation he must seek success principally by his straightforward and honest procedure, for if he attempts to succeed by subtlety or by a sense of superiority over those with whom he is engaged he may very likely deceive himself. There is no prince or state which does not possess some shrewd envoy to discern its real interests. And indeed, even among people who seem to be the least refined, there are often those who know their own interests best, and follow them with the most constancy. Therefore the negotiator, no matter how able he may be, must not attempt to teach such persons their own business, but he should exhaust all the resources of his mind and wit to prove to them the great advantage of the proposals which he has to make. [Sidenote: _Diplomacy a Commerce in Benefits._] An ancient philosopher once said that friendship between men is nothing but a commerce in which each seeks his own interest. The same is true or even truer of the liaisons and treaties which bind one sovereign to another, for there is no durable treaty which is not founded on reciprocal advantage, and indeed a treaty which does not satisfy this condition is no treaty at all, and is apt to contain the seeds of its own dissolution. Thus the great secret of negotiation is to bring out prominently the common advantage to both parties of any proposal, and so to link these advantages that they may appear equally balanced to both parties. For this purpose when negotiations are on foot between two sovereigns, one the greater and the other the less, the more powerful of these two should make the first advance, and even undertake a large outlay of money to bring about the union of interests with his lesser neighbour, for his own self-interest will show him that he has really the greater object and the larger advantages in view, and that any benefits he may confer or subsidies which he may grant to his weaker ally will be readily repaid by the success of his designs. Now, as we have said, the secret of negotiation is to harmonise the interests of the parties concerned. It is clear that if a negotiator excludes the honest and straightforward method of reason and persuasion, and adopts on the contrary a haughty and menacing manner, then obviously he must be followed by an army ready to invade the country in which he has put forth such provocative claims. Without such a display of force his claims will fall to the ground, even though by advantageous arguments they might have prevailed with the prince whom he addressed, and who might have accepted them had they been proposed