In the context of the increasingly polarized political debate in the Western world, it is striking that many claims are made in the name of the law about the possible or necessary level of social acceptance of foreign-ness1. Law—usually in its constitutional variety—is invoked to justify various forms of closure, protectionism and differentiation between the home-grown and the foreign, in the name of community values, tradition, culture, or sovereignty. The rise of identity politics, linked to fear that rising levels of immigration threaten national cultural integrity, means that, most frequently, such claims tend to be framed in the terms of intolerance or exclusion rather than in those of tolerance, or indeed hospitality. In this respect, one salient feature about these contemporary political controversies—which are echoed most topically today in debates over Brexit, immigration control, President Trump’s ‘travel ban’ or the status of migrants—is the extent to which they focus on the supposed requirements of the law in relation to the defence of identity and the acceptance of otherness. While such debates tend to focus on the foreigner (alien, immigrant), they also concern institutions, practices, life-styles (or Lebensform), convictions, worldviews, and foreign law. [First paragraph]