On Monday, RTL invited not one but two special guests on the radio, with the afternoon guest being one of Germany's best-known columnists and authors.
Harald Martenstein's writing is critical, and he himself is frequently on the receiving end of criticism.
Whether in the past at Der Tagesspiegel or Die Zeit, or today at Bild, he writes what he believes to be right. His latest take being for instance that banning the far-right Alternative for Germany (AfD) in Germany would be counterproductive.
He has faced criticism from the left, and drawn praise from the right.
If a party argues against banning another party, Martenstein said, then this means the party is in favour of such a measure and that they wouldn't protest against such a thing. He himself, he added, is against banning any of Germany's other relevant parties.
In his columns and in his new book, Martenstein defends freedom within a democracy. On that basis, he argues for tearing down the "firewall" against the AfD.
No one, Martenstein pointed out, was permitted to cooperate with the AfD in the slightest. Behind that ban, he said, lay an unspoken all-party coalition.
Reaching agreement within such a set-up was, naturally, difficult, since all these parties held very different fundamental positions. As a result, little to nothing gets done.
Since Germany seemed, in his view, to be at a standstill, people were looking for a change of direction. One has to learn from experience, Martenstein said.
The firewall has caused the AfD to grow steadily stronger and the Christian Democratic Union of Germany (CDU) to grow steadily weaker. If the CDU wants to continue becoming weaker, it should carry on down that road, the columnist warned.
Martenstein is not intimately familiar with the ins and outs of Luxembourg politics. The Christian Social People's Party (CSV), however, which had invited him to Luxembourg to give a talk and reading on the eve of its parliamentary conference, would be well advised, in his view, to avoid the mistakes made by its German sister party, the CDU.
It was a mistake, Martenstein said, to rule out any option for cooperation from the outset. That took away room to move politically, which is after all political capital.
Prime Minister Luc Frieden's party has, so far, consistently ruled out any cooperation with the right-wing populist Alternative Democratic Reform Party (ADR).
Martenstein is not making a case for the AfD. He condemns its pro-Russian views, and finds its economic policy rather odd.
The author argues, however, that the AfD is not a new Nazi Party, and one could not accuse the party of militarism.
Martenstein, in short, says and writes things that do not always sit well with everyone.
"You become controversial when you notice something before others do", Martenstein explained.
As far back as 2015, for instance, Martenstein spoke out against excessive, uncontrolled migration into Germany.
He has also been critical of the ban on combustion engines and of the use of gender-neutral language. "Woke" culture, he said, was not for him.
Worldviews that sought to pin everything bad and evil on a single cause, Martenstein argued, were questionable.
Whether it was the Devil, or capitalism, without which we would supposedly all be happy, or indeed white men, without whom everyone in the world, including white men themselves, would supposedly be happy.
That, he said, was what made this kind of narrative questionable. It was a machine for explaining the world through a single cause.
Martenstein does, however, clarify his criticism of gender-inclusive language. He was not, he said, fundamentally against people using it. He was, however, against being told to use it.
Which brings us back to the freedom that is so essential to author and columnist Harald Martenstein.
