This paper uses scientific perspectivism as a lens for understanding acid experiments from the Chemical Revolution. I argue that this account has several advantages over several recent interpretations of this period, interpretations that do not neatly capture some of the historical experiments on acids. The perspectival view is distinctive in that it avoids discontinuity, allows for the rational resolution of disagreement, and is sensitive to the historical epistemic context.

According to best systems accounts, laws of nature are generalizations in the best systematization of particular matters of fact. Metrics such as simplicity and strength determine which systematization is best, but these are notoriously language relative. For this reason, David Lewis proposed a constraint on languages of inquiry: all predicates must be natural. This constraint is sometimes interpreted as requiring us to know which natural properties are instantiated in our world prior to scientific theorizing. I argue that this interpretation is (...) incorrect. I provide a better interpretation and show how it undercuts an influential epistemological objection to Lewis's best systems account of laws due to Bas van Fraassen. (shrink)