The ambassador must know what the Government of the state where he is will do.

A false diagnosis is discreditable.

But it is impossible for a representative, whoever he may be, to obtain such power over a foreign state as to be able to guide the policy of that state into the course desired by him.

The policy of a state will invariably be subservient to such objects as the Government of that period deem vital, and will always be influenced by factors which are quite outside the range of the foreign representative.
In what manner a diplomatic representative obtains his information is his own affair.

He should endeavour to establish intercourse, not only with a certain class of society, but also with the Press, and also keep in touch with other classes of the population.
One of the reproaches made to the "old regime" was the assumed preference for aristocrats in diplomacy.