This Special Issue was selected by a dedicated ESHS committee after a public call for special issues.
AbstractThe periodic system is an icon of science, with an exceptional level of usage around the world. It is especially celebrated as a source of information and pedagogical tool.Although many publications on the history and philosophy of the system have appeared over the years, few of them deal with its underlying values aside from predictability. In this issue, scholars from different disciplines use the history of the periodic system to discuss what the system signifies and has signified for scientists and teachers, as well as for philosophers and historians. By presenting different layers of underlying values as they appear in the eyes of the users, we aim to provide a richer understanding of the periodic system, past and present. K E Y W O R D S paper tool, pedagogical tool, periodic system, relational tool, resilience, thing valueIn his book Scientific Babel, Michael D. Gordin states that the periodic system of chemical elements "was the single most important discovery of inorganic chemistry in the nineteenth century-and quite possibly of chemistry in general, in any century," and it is frequently referred to as an icon in science. 1 Indeed, the fact that we can find the periodic system in more or less every chemistry classroom and lecture hall in the world today testifies to its importance in chemistry, both as a source of information or compass, and as a pedagogical tool. The periodic system is said to "capture the essence not only of chemistry, but also of physics and biology" and is described as a "unique tool, enabling scientists to predict the appearance and properties of matter on the Earth and in the rest of the Universe." 2The position a chemical element occupies in the periodic system informs us about its chemical properties, as elements belonging to the same groups, or families (vertical columns in the most common periodic tables), exhibit similar