Function, Fashion and Finance: A new sense of architectural purpose for the City?

What is the future of the city in the modern world, and, in particular, what is the role of London in the next century? We live in a time of unprecedented instability in which the unknowns of economics and politics seem greater than ever. Yet the places we love most were the products of relatively long established and stable societies and based on the apparent certainties of religious faith. Our skills as architects, planners and engineers derive from those times and we find it difficult to handle growth and change and to design confidently for impermanence. What then can we do to help?