Mary Shepherd : Oxford University Press : 9780190090333 : 0190090332 : 21 Feb 2023 : "This guide leads readers systematically through the arguments of Mary Shepherd's two books. Chapters 1-4 cover the arguments in the Essay Upon the Relation of Cause and Effect (1824), where Shepherd argues that causal principles can be known by reason to be necessary truths and that causal inferences can be rationally justified. Shepherd's primary target in this work is Hume, but she also addresses the views of Thomas Brown and William Lawrence. Shepherd considered her second book, Essays on the Perception of an External Universe, and Other Subjects Connected with the Doctrine of Causation (1827), to be an extension of the earlier project on causation; here she appeals to the causal principles established in the first book to argue that we can know through reason that an external world of continually-existing objects must exist independently of us, as the causes of our sensations. Chapter 5 of this Gu