As Theresa May plays the hand that history has granted her with the triggering of Article 50, I am struck by the contrast between the “national conversation” about Brexit in parliament and in the media, and the realities of life elsewhere. While Westminster laments, people and businesses across Britain are getting on with meeting the new challenges. It is perhaps inevitable that some are still looking backwards. Parliament is the crucible of our country’s hopes and fears, a stage on which the different phases of grief have to be acted out. Some extinct volcanoes must be allowed a final splutter. But in focusing all their energies on resistance and delay, those who oppose Brexit are writing themselves out of the essential debate about how Britain forges a strategy to deliver prosperity for future generations. This is an “unfrozen moment” in our history, the beginning of a new era. We should all be using it as a moment of national self-examination, to think of the long term. So what should a post-Brexit economy look like? I believe there are four essential pillars. First, as the prime minister has said, Britain needs to become the world’s beacon of free trade. We, of course, must sign a free-trade deal with the EU itself. But we also need to forge new deals with the US, Australasia, India and China and emerging markets. For too long progress in world trade liberalisation has been stalled by the unwillingness of the US and Europe to open their agricultural markets. Britain can break the logjam through a landmark “agriculture for services” deal. For this to happen, Britain needs to leave the single market and the customs union. While we remain a member, we are not allowed to sign independent trade deals. Diehard Remainers are beginning to understand this. “Soft Brexit” was never an option if we are to become a global free-trading nation. The second pillar is to redouble our efforts to build a knowledge-based economy. That means putting universities at the centre of a national strategy to unlock the UK’s intellectual property and harness it to our commercial interests. Our universities are one of Britain’s greatest assets and potentially one of our greatest exports. They are a magnet for young talent and a font of international goodwill. For countries like India, access to our universities will be a key component of any trade deal. With this in mind the prime minister needs to make sure that students are taken out of the immigration numbers so that there are no unnecessary obstacles to the flourishing of this sector. The third pillar is deregulation. Industries like biotechnology, agribusiness, ports, energy and fintech have all been held back by EU regulations and now have the opportunity to innovate and expand in ways that were not previously possible. The fourth pillar is investment. It might serve the cabinet well to schedule an away-day in Leipzig (which I recently visited). Thirty years ago the hometown of Bach and a great centre of international trade was a rundown city in communist East Germany. Three decades of public and private investment have helped reclaim past glories. Porsche and BMW have both built factories. Road and rail infrastructure is state of the art; the city centre is green and well ordered. Britain needs to have the same vision for its great provincial cities outside London. The Germans have understood that well-targeted infrastructure investment produces long term economic pay-offs. Treasury accounting needs to move beyond the ledger of the annual budget balance and make a stronger distinction between investment and consumption. Investment also – and perhaps above all – means investing in our people. Our universities may be first class; our vocational training has been an educational Cinderella. To compensate the decades of neglect, vocational training needs a new status at the heart of government, perhaps with its own Cabinet position. Brexit is a huge opportunity for our country. It calls for great leadership, both in government and business. It also calls for unity. It is time to move beyond grief and resentment and to combine our energies in a common endeavour. Let’s use this unfrozen moment to create a new era of national prosperity.