A collective right to the city A collective right to the city was seminally articulated by the French philosopher Henri Lefebvre, a right understood not simply as individual access to the goods, services, and spaces of the city but as the right to change the city in accordance with our deepest desires, to steer the very process of urbanization and the way in which the city nurtures the kinds of people we wish to become. Michael Sorkin, 20 Minutes in Manhattan The Help-Yourself City rights
Materials and how to employ them Forming a paper clip presents a common dilemma encountered by engineers and inventors: the very properties of the material that make it possible to be shaped into a useful object also limit its use. If one were to try and make a paper clip out of wire that stayed bent too easily, it would have little spring and not hold papers very tightly. On the other hand, if one were to use wire that did not stay bent, then the clip could not even be formed. Thus, understanding the fundamental behavior of materials and how to employ them to advantage is often a principle reason that something as seemingly simple as a paper clip cannot be developed sooner than it is. Henry Petroski, The Evolution of Useful Things Ideas behind their time material