Maxwell's role in turning the concept of model into the methodology of modeling.

This is a contribution towards a history and philosophy of modeling in its early stages in electromagnetism. In 1873, James Clerk Maxwell (1831-1879) hinted at the methodology of modeling at the end of his Treatise on Electricity and Magnetism. We focus on Maxwell's impact on physicists who immediately followed him, specifically Oliver Lodge (1851-1940) and George Francis FitzGerald (1851-1901). We begin with the role that the scientific concept of model played in the late nineteenth century, as assessed by Ludwig Boltzmann (1844-1906). We then discuss the role of hypothesis as a methodology, the appeal to (dynamical) illustration, and the way Maxwell applied model and working model in his studies of electromagnetism. We show that for Maxwell these key terms were kept distinct, but Lodge did not maintain these distinctions and, in this regard, FitzGerald followed Lodge. Notwithstanding Lodge's influence, Fitzgerald modified Maxwell's theory based on the mechanical model he designed, thereby implicitly taking the first step towards modeling. This methodology consists in drawing consequences from the (mechanical) model to the (electrodynamic) theory and modifying the latter in light of the functioning of the former. At the core of our argument is the thesis that it was a methodological novelty to move from the concept of model to the methodology of modeling. The introduction of modeling as a new methodology into physics in the late nineteenth century was a major event which deserves proper recognition.

'Natures' and 'Laws': The making of the concept of law of nature - Robert Grosseteste (c. 1168-1253) and Roger Bacon (1214/1220-1292).

Contemporary scholars set the Greek conception of an immanent natural order in opposition to the seventeenth century mechanistic conception of extrinsic laws imposed upon nature from without. By contrast, we argue that in the process of making the concept of law of nature, forms and laws were coherently used in theories of natural causation. We submit that such a combination can be found in the thirteenth century. The heroes of our claim are Robert Grosseteste who turned the idea of corporeal form into the common feature of matter, and Roger Bacon who described the effects of that common feature. Bacon detached the explanatory principle from matter and rendered it independent and therefore external to natural substances. Our plausibility argument, anchored in close reading of the relevant texts, facilitates a coherent conception of both 'natures' and 'laws'.