Nineteenth-century chemists were faced with a particular problem: how to depict the atoms and molecules that are beyond the direct reach of our bodily senses. In visualizing this microworld, these scientists were the first to move beyond high-level philosophical speculations regarding the unseen. In Image and Reality, Alan Rocke focuses on the community of organic chemists in Germany to provide the basis for a fuller understanding of the nature of scientific creativity. 

Arguing that visual mental images regularly assisted many of these scientists in thinking through old problems and new possibilities, Rocke uses a variety of sources, including private correspondence, diagrams and illustrations, scientific papers, and public statements, to investigate their ability to not only imagine the invisibly tiny atoms and molecules upon which they operated daily, but to build detailed and empirically based pictures of how all of the atoms in complicated molecules were interconnected. These portrayals of “chemical structures,” both as mental images and as paper tools, gradually became an accepted part of science during these years and are now regarded as one of the central defining features of chemistry.  In telling this fascinating story in a manner accessible to the lay reader, Rocke also suggests that imagistic thinking is often at the heart of creative thinking in all fields.

Image and Reality is the first book in the Synthesis series, a series in the history of chemistry, broadly construed, edited by Angela N. H. Creager, John E. Lesch, Stuart W. Leslie, Lawrence M. Principe, Alan Rocke, E.C. Spary, and Audra J. Wolfe, in partnership with the Chemical Heritage Foundation.

New scientific ideas are subjected to an extensive process of evaluation and validation by the scientific community. Until the early 1980s, this process of validation was thought to be governed by objective criteria, whereas the process by which individual scientists gave birth to new scientific ideas was regarded as inaccessible to rational study. In this book Gerald Holton takes an opposing view, illuminating the ways in which the imagination of the scientist functions early in the formation of a new insight or theory. In certain crucial instances, a scientist adopts an explicit or implicit presupposition, or thema, that guides his work to success or failure and helps determine whether the new idea will draw acclaim or controversy. Using firsthand accounts gleaned from notebooks, interviews, and correspondence of such twentieth-century scientists as Einstein, Fermi, and Millikan, Holton shows how the idea of the scientific imagination has practical implications for the history and philosophy of science and the larger understanding of the place of science in our culture. The new introduction, "How a Scientific Discovery Is Made: The Case of High-Temperature Superconductivity," reveals the scientific imagination at work in current science, by disclosing the role of personal motivations that are usually hidden from scientific publications, and the lessons of the case for science policy today.