Daniel Liu (Urbana/Berlin)
Just as the history of the luminiferous ether is essential to the history of classical physics, in this lecture I will argue that the history of protoplasm is essential to understanding some of the basic dynamics of a “classical” period in the history of biology; these include the development of cell biophysics, alternative theories of genetic inheritance, and the search for a “fine structure” of the cell. Protoplasm was one of the central organizing concepts of biology between the 1840s and the 1940s, yet it was an idea whose full implications could be hard for biologists to grasp. Although the term was originally conceived by Hugo Mohl as an anatomical term in plant cell theory, by the 1860s protoplasm had become synonymous with “living matter” and even “life” itself in the materialist paradigm of modern physiology. For nearly a century protoplasm was: a cell anatomical theory (of, ironically, a formless mass), a cultural-scientific slogan, a level of biological investigation, a motivation for reductionism, a backstop against reductionism, a protean substance whose properties could be manipulated…and more. Protoplasm thus became the central site at which properties formerly relegated to living things shifted to simpler materials that were not, strictly speaking, alive. Yet, in hindsight, it was not the ground from which modern biochemistry developed. As such, the history of protoplasm offers a unique perspective to understand the molecular revolution that divides the history of the modern life sciences.