Absolutism about mass within Newtonian gravity claims that mass ratios obtain in virtue of absolute masses. Comparativism denies this. Defenders of comparativism promise to recover all the empirical and theoretical virtues of absolutism, but at a lower ‘metaphysical cost’. This article develops a Machian form of comparativism about mass in Newtonian gravity, obtained by replacing Newton’s constant in the law of universal gravitation by another constant divided by the sum over all masses. Although this form of comparativism is indeed empirically (...) equivalent to the absolutist version of Newtonian gravity—thereby meeting the challenge posed by the comparativist’s bucket argument—it is argued that the explanatory power and metaphysical parsimony of comparativism are highly questionable. (shrink)

In the course of his researches in electromagnetism and the kinetic theory of gases, James Clerk Maxwell gave some thought to the nature of science itself. His observations in this field are of interest today not only because they are his, but because they are still instructive. Maxwell's views are to be found in the many asides with which he enlivened his scientific papers and treatises and in the various articles and reviews which he prepared for more popular consumption. The (...) topics discussed bear on his own contributions to physics; they include the logic of dynamical explanation, the method of physical analogy, and the perennial question of action at a distance versus contiguity. In the present essay, I wish to discuss Maxwell's views on dynamical explanation. (shrink)