Abstract
In several early 19th century works, Mary Shepherd articulates a theory of causation that is intended to respond to Humean skepticism. I argue that Shepherd's theory should be read in light of the science of the day and her conception of her place in the British philosophical tradition. Reading Shepherd’s theory in light of her conception of the history of philosophy, including her claim to be the genuine heir of Locke, illuminates the broader significance of her attempt to reinstate reason as the source of scientific knowledge. Reading Shepherd's theory in light of the science of the day helps make plausible her claim that there are robust natural kinds in nature, defined by their causal powers: this is precisely what then-recent advances in chemistry hold.