The stability of species. Take the number of species that we now consider extinct. For a long time scientists took the number of such species as that implied from an analysis of the extant fossils.

The concept of mobility blends the material and philosophical. It raises questions such as: Why are we moving, and what do those shifts reveal about our needs and desires? Then there are political and legal questions to explore: Who is allowed to move? What restrictions do we face on movement and why? And last but not least, there are normative questions: Where should people go? What is the optimal distribution of people around the world? Mobility is also an intangible and spiritual experience. Pause and appreciate how fluidly our anatomy carries us. Moving stimulates creativity, the process of witnessing ways of life coming together.

Khanna, P. (2021) Move: The Forces Uprooting Us. New York, N.Y: Scribner.

We are told not only that movement through geographies can be stopped but that movement through time can be too, that we can return to the past, to a better past, when our country, our race, our religion was truly great. All we must accept is division. The division of humanity into natives and migrants. A vision of a world of walls and barriers, and of the guards and weapons and surveillance required to enforce those barriers. A world where privacy dies, and dignity and equality alongside it, and where humans must pretend to be static, unmoving, moored to the land on which they currently stand and to a time like the time of their childhood—or of their ancestors’ childhoods—an imaginary time, in which standing still is only an imaginary possibility. Such are the dreams of a species defeated by nostalgia, at war with itself, with its migratory nature and the nature of its relationship to time, screaming in denial of the constant movement that is human life.

Mohsin, H. (2019) ‘In the 21st century, we are all migrants’, National Geographic magazine, August. Available at: https://www.nationalgeographic.com/magazine/article/we-all-are-migrants-in-the-21st-century.