The aim of this paper is to show how thought experiments help us learn about laws. After providing examples of this kind of nomic illumination in the first section, I canvass explanations of our modal knowledge and opt for an evolutionary account. The basic application is that the laws of nature have led us to develop rough and ready intuitions of physical possibility which are then exploited by thought experimenters to reveal some of the very laws responsible for those intuitions. (...) The good news is that natural selection ensures a degree of reliability for the intuitions. The bad news is that the evolutionary account seems to limit the range of reliable thought experiment to highly practical and concrete contexts. In the fifth section, I provide reasons for thinking that we are not as slavishly limited as a pessimistic construal of natural selection suggests. Nevertheless, I promote the idea that biology is a promising source of predictions and diagnoses of thought experiment failures. (shrink)

This paper discusses some philosophical and historical connections between, and within, nineteenth century evolutionism and microscopical research. The principal actors are mainly Darwin, Schleiden, Whewell and the “London Doctors,” Arthur Henfrey and Edwin Lankester. I demonstrate that the apparent alliances—particularly Darwin/Schleiden (through evolutionism) and Schleiden/Whewell (through Kantian philosophy of science)—obscure the deep methodological differences between evolutionist and microscopical biology that lingered on until the mid-twentieth century. Through an understanding of the little known significance of Schleiden’s programme of microscopical research and (...) by comparing certain features of his methodology to the activities of the “London Doctors,” we can identify the origin of this state of affairs. In addition, the outcome provides an insight into a critique of Buchdahl’s view on Schleiden’s philosophical conception. (shrink)