If I think of Germany at night, I still sleep soundly. But after the recent bruising assertion of German power in the eurozone, especially during the hellish all-night Brussels dance along the precipice of Grexit in mid-July, I’m not alone in feeling the first twinges of insomnia. The fact that there are so many things the Germans have got right should not stop us, and them, from asking what they have got wrong – or at least, could do better. I have been chewing this over, and come up with a surprising thought: to achieve more consensus abroad, perhaps Europe’s leading power needs less consensus at home.

As it happens, this week sees the 40th anniversary of the signing of the Helsinki Final Act, a milestone on the journey that led eventually to today’s united Germany, with its East German chancellor and president. It is interesting to go back and sample the style of German foreign policy at that time: patiently multilateral, modest, humble even, and yet with touches of the inspirational, as in the rhetoric of Willy Brandt and Richard von Weizsäcker.

Much of this policy tradition has survived. It’s worth remembering that, in the Brussels night of the long jibes, Germany was also speaking for a group of smaller north and north-east European states. Some of their leaders make German finance minister Wolfgang Schäuble sound like an old softie. Moreover, you cannot realistically expect a united Germany, now Europe’s central power, to act exactly like the old West Germany 40 years ago – especially when it’s being asked to put more billions of euros on the table for a policy most of its people don’t believe in.

Nonetheless, the humiliating demands made of Greece, and the style in which they were made, shocked many of the country’s partners and friends. Yet at home, while a few important figures such as Jürgen Habermas and Joschka Fischer sounded alarm bells, the hard line represented by Schäuble commanded wide support. In fact, the only reason that the rebellion against the Greek bailout deal in the parliamentary ranks of the centre-right CDU/CSU was not even larger than it was is that Schäuble put his authority behind an agreement he had not wanted. “Mistrust of Greece has grown enormously,” said Hans-Peter Friedrich, a conservative former interior minister. “Actually, we’re not for a third bailout package, but Wolfgang Schäuble deserves our support.”’ (So Friedrich has one thing in common with Alexis Tsipras: he voted for a deal he doesn’t believe in.)

Schäuble is one of the most remarkable politicians I have known. He was impressive already as a younger man, at the right hand of Helmut Kohl, negotiating German unification and advocating European unity. But to have carried on at the highest level of politics for a quarter-century since an assassination attempt put him in a wheelchair, fulfilling a packed schedule that would exhaust an Olympic athlete half his age, yet still with intellectual verve and combative good humour – that is an extraordinary human achievement. It manifests virtue in the original sense, combining morality and vigour. What is more, Schäuble one of the most consistently pro-European voices in German politics. Yet the interview he gave to the German news magazine Der Spiegel after the Brussels horror fest is a strange and frankly worrying mishmash.

I don’t think the homespun wisdom of Dr Schäuble’s granny should be the thread upon which the future of Europe hangs

While insisting that a European political union is needed to complement the monetary one, and that this will at some point require changes to the European treaties (but don’t get your hopes up, David Cameron, for this will not happen in your referendum time frame), Schäuble is completely unbending on Greece. He insists there was nothing wrong with his austerity prescription: “The problem is that for the last five years the medicine has not been taken as prescribed.” As for the debt relief which the IMF says is essential: “Debt relief is not possible within the currency union. European treaties do not allow it.” Basta.

Asked about his toughness with Greece, the English version of the interview has him explain that “my grandmother used to say: benevolence comes before dissoluteness”. Dissoluteness? In the German original, the word his Swabian granny used is Liederlichkeit. I looked it up in Duden, the reference work for the German language, and Duden’s long list of synonyms is fascinating. They include (roughly translated) slovenliness, carelessness, inaccuracy, dirtiness, disorderly working, and several other words that together perfectly capture German negative stereotypes of feckless, idle south Europeans.

I somehow don’t think the homespun wisdom of Dr Schäuble’s grandmother should be the thread upon which the future of Europe hangs. Personal virtue, political will, respect for the letter of the law: all these are admirable qualities that the German finance minister both advocates and personifies, but at the end of the day what matters is what will work. Yes, economists talk a good deal of nonsense, but there are economic realities. Some things are possible, others not. For example, Greece cannot repay its debts.

There is now a hard, realistic argument to be had about what will actually work best, and that is raging around both Germany and Greece. But is this argument being had enough inside Germany? I may be wrong, but my impression is that it is not. Consensus is one of the great strengths of the Federal Republic, and change through consensus is a German speciality, personified by Chancellor Angela Merkel. Change through consensus is how the country achieved the painful labour and welfare reforms which in the early 2000s positioned it to take spectacular advantage of the opportunities offered by the eurozone. (Germany’s trade surplus has almost quadrupled since the turn of the millennium, to well over €200 billion, about 7% of its GDP.)

But sometimes you can have too much consensus, and what I encounter in Germany is almost a pensée unique. Even before a German economist opens his mouth, you know what he is going to say about the eurozone. The exceptions are few and far between.

The German media compensate for this with bracing outside voices. The leading liberal weekly Die Zeit, for example, published an interview with Thomas Piketty, who described Germany as “really the prime example of a country which in its history has never paid back its public debts. Neither after the first world war nor after the second world war.” But these outside provocations don’t quite make up for the smothering consensus within. A little more reality-based controversy would be welcome: not futile, US-style dysfunctional partisanship, but the good meat of deliberative democracy.

It’s not as if there is any shortage of gifted, independent-minded German thinkers, young and old. It’s just that many of them are either keeping their heads down or living and working abroad. Heinrich Heine was living in exile when he penned his famous lines about not being able to sleep if he thinks of Germany at night. Of course no one needs to leave Germany for political reasons today, but maybe there are more subtle social and cultural ones.

I would hate to lose a single one of my brilliant German colleagues and students, whether at Oxford, Stanford or the Guardian, but I think the homeland could use a few more of them – and the constructive controversy they would bring.