Deputy Speaker Lindsay Hoyle put it well when he said: "We lost one of our village policemen. This is our village." But as well as being a community of more than 2,000 people who work here, it is in the end the nation's Parliament. Westminster has for too long been portrayed as the 'other', as a place disconnected from the rest of the country. And an attack on it is an attack on us all. That's why we'll keep calm and carry on today.