Most recent philosophical thought about the scientific representation of the world has focused on dyadic relationships between language-like entities and the world, particularly the semantic relationships of reference and truth. Drawing inspiration from diverse sources, I argue that we should focus on the pragmatic activity of representing, so that the basic representational relationship has the form: Scientists use models to represent aspects of the world for specific purposes. Leaving aside the terms "law" and "theory," I distinguish principles, specific conditions, models, (...) hypotheses, and generalizations. I argue that scientists use designated similarities between models and aspects of the world to form both hypotheses and generalizations. (shrink)

This article attempts a contextual study of the origin and early development of August Kekulé's theory of aromatic compounds. The terminus a quo is essentially August Hofmann's coining of the modern chemical denotation of ‘aromatic’ in 1855; the terminus ad quem is the first full codification of Kekulé's theory in the sixth fascicle of his Lehrbuch der organischen Chemie, published in the summer of 1866. Kekulé's theory is viewed in context with the earlier and concurrent experimental work of such chemists (...) as Hermann Kolbe, Friedrich Beilstein, Rudolph Fittig, and Hugo Müller. The reception of the theory is briefly examined. Attention is paid to the role of Kekulé's molecular models and of his celebrated dream anecdote of the snake that seizes its own tail. The episode is used as a case study for the continuity of scientific progress, and to illustrate the close reciprocal interactions of hypothesis and experiment in the evolution of a scientific theory. (shrink)