Daniel Liu (plenary), “Ending Epigenesis: Cell and Protoplasm as Developmental Agents, 1828–1850”
Channel: CEFISES at UCLouvain
Date: 2023-08-08

Talk given at the Mechanisms and Ontic Causation in the Life Sciences conference, the second workshop of the MeCauLife group.

Abstract: At the end of the 18th century a generation's worth of the preformation vs. epigenesis debates faded away. Unresolved, these debates were set aside in favor of more descriptive approaches to morphogenesis that nevertheless built on C. F. Wolff's description of the coagulation of tissues from an unorganized formative substance. In this lecture(*) I will explore the persistence of semi-epigenetic theories of development up to the middle of the nineteenth century, and the role they played in the development of cell theory in the 1830s and 1840s. I will show that biologists developed several different strategies for making causal claims about the genesis and physiological role of cells. I will make the somewhat unorthodox argument that we can see cell theory as having less to do with microscopy, epigenesis, or theories of vital forces. Instead I will suggest we can understand the development of cell theory by 1850 as partly a negotiation by biologists over the role of chemistry in biological argument, ending with the declaration that the cell's protoplasm was both the so-called “living substance” and the causal source of morphogenesis.