Speaking in Thursday's edition of Die Zeit newspaper, Philip stressed that a monarch would be financially independent – and so would not be likely to accept presents from friends, such as those which led to Christian Wulff's resignation from the presidency.
"A king is invulnerable to such cases," Prince Philip said. "Either he would have old family property or an Apanage – and it would be beneath his dignity to accept presents from friends."
"And there are no reporters on the level of sniffing around European ruling families,” added the prince, who is a Protestant minister.
Prince Philip said that although successful presidents made their mark with their statements, mentioning Roman Herzog and Richard von Weizsäcker as good examples, he said that words were not enough.
“This level of words is necessary, but they do not move people inside,” he said. “When our hearts are touched, we change. During the past football World Championship there emerged so much uncomplicated national consciousness that nose-wrinkling intellectuals no longer understood their country.
“Emotions are the field on which a royal family can play," he said. "They do not have to think up some programme, it goes to the hearts that they are simply there.”
He said the personal and family lives of politicians were regarded as private – but that those of royals were legitimately public.
“Of course a king should have a happy marriage. Of course the heir to the throne should marry,” he said.
And even the question of royal children was a legitimate matter for the public, he said. “When, as now in Sweden, a member of the royal family is born, what a joy goes through the country! Even the prime minister spoke of a happy day. The heart has a much more intensive influence than the appeal of the family minister for better framework conditions to combine family and career.”
The collapse of royal marriages can even be good for the country, he suggested, because the media scandalises bad behaviour conducted by royals. The collapse of a politician's marriage is regarded as private, he said, or seen as part of a modern family.
The lives of a royal family lend a country stability, he said. “They are not thrown out by a vote of confidence or swept from office by their immunity from prosecution being lifted. That does a country good.”
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He suggested that German politicians would even vote for a royal family to be reinstated, if it came to a vote – nearly a century after the last Kaiser was removed from the throne in 1918. Even left-wingers would be in favour, he suggested, pointing to Sweden where he said some socialists were also royalists.
But even if the German royal family were to be reinstated, Prince Philip would not sit on the throne – that honour would go to Prince Georg Friedrich von Preußen, who is the direct heir and has said he would not want to see a royal restoration.