CRASSH 'Understanding Society' lectures supported by the Thriplow Charitable Trust: www.crassh.cam.ac.uk/11. Richard Sennett will focus on the relation of social life to physical design. In this lecture he'll explore what shape cities should have to admit the complexities and conflicts of the people who live together, in a particular way. He'll talk about edge conditions within the city, distinguishing between borders and boundaries, exploring the design of porosity and mixture of people who differ from one another.