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Those who gather intelligence from another country on the authority of the State act as public ministers.
Also if a man be sent into another country, secretly to explore their counsels and strength; though both the authority and the business be public, yet because there is none to take notice of any person in him, but his own, he is but a private minister; but yet a minister of the Commonwealth; and may be compared to an eye in the body natural. And those that are appointed to receive the petitions or other informations of the people, and are, as it were, the public ear, are public ministers and represent their sovereign in that office.
Hobbes, Lev XXIII 12