Mary Shepherd was born in Scotland at her family’s estate on December 31, 1777, the second daughter of Neil Primrose, Earl of Rosebery; she died in London on January 7, 1847. Relatively few details of her life and education are available. She married an English barrister, Henry Shepherd, in 1808.
She published at least two works in philosophy, An Essay upon the Relation of Cause and Effect (1824), and Essays on the Perception of an External Universe and other Subjects Connected with the Doctrine of Causation (1827).
A third work, originally published anonymously in 1819, Enquiry respecting the Relation of Cause and Effect, has been credited to her, but it differs so significantly from her other work, both in style and content, as to make this attribution dubious. She was as well a participant in an exchange of views with a contemporary, John Fearn, which appeared in various venues.
Shepherd’s work reflects the continued interest in the first quarter of the nineteenth century in developing alternative arguments to those of Hume, conceived largely skeptically. Her first work establishes the line of argument that was to direct her work. In it, she seeks to refute Hume’s position on causality by arguing that Hume is mistaken in holding that we lack an intuitive understanding that events have causes.
Shepherd reads Hume as holding that we cannot be intuitively certain that everything that begins to exist has a cause, and subjects to criticism the contained concept of a causeless beginning-to-be of some existence. Her argument is that this beginning is itself an action and hence must be a state of something that, by hypothesis, does not as yet exist until it has begun to be.
Hence, she claims, the basic assumption of Hume’s account is contradictory. Shepherd offers a realist account of cause as the productive principle of effects, themselves not subsequent to causes, but rather coexistent with the productive object. She uses her realist understanding of causation to criticize not only Hume, but also her own contemporaries, Thomas Brown and William Lawrence.
|Essays on the Perception of an External World|
Shepherd’s second work, Essays on the Perception of an External World, was originally intended as an appendix to her first work and consists primarily, although not exclusively, of an application of her ideas about causation to the question of the existence of an external world. By far the largest part is directed to providing an alternative answer to Hume’s question about the sources of our idea of a continuous external existence.
Appended are a series of essays about Berkeley, Reid, Stewart, Hume, and what Shepherd terms in the title of her work “various modern atheists.” Shepherd argues, against Hume, that the possibility of causal reasoning, as demonstrated in her first book, makes such reasoning available to substantiate the existence of a continuously existing independent world.
She feels it necessary, however, to give a different solution from that of Reid. This is because she thinks Reid failed to appreciate the importance of Berkeley’s claim that an idea can only be like another idea. Shepherd takes this to mean that Reid is wrong to suppose that we can give content to our ideas of a mind-independent world.
Thanks to the possibility of causal reasoning, however, we are able to assert the existence of causes responsible for our ideas. In particular, because our ideas change, there must be causes for these changes, independent of our ever-present mind. The variety we experience must be due to causes other than ourselves, whose nature, while unknown, must be, she thinks proportional to their effects.
Shepherd develops and clarifies these ideas further in her exchange of views with John Fearn, a retired naval officer and philosophical aficionado. This exchange is unusual as well as interesting, presenting one of the first occasions where a woman’s ideas are attacked in print, and illustrating some of the different venues available to ordinary practitioners for publishing philosophy in the early nineteenth century.
The first two parts of the exchange appear in 1828 in a volume loosely related to the clergyman, Samuel Parr, called Parriana, apparently supplied by Fearn to its compiler, Ernest Barker, and included by him, despite the lack of relevance to Parr.
These consist of a four-page paper, critical of Fearn by Shepherd, apparently sent to him privately, and a longer defense of his views against Shepherd by Fearn. Shepherd was sufficiently concerned by this unauthorized use of her work that she published a rebuttal, “Lady Mary Shepherd’s Metaphysics” in a well-known literary journal, Fraser’s Magazine, in July 1832.
The exchange focuses on a disagreement over the idea of extension. It is Fearn’s view that the content of the idea of extension is determined by our perception of it. There can be no extended external material cause of such an idea. The only possible cause consists of the energies of an extended mind, analogous to our own. Shepherd maintains that Fearn has not adequately distinguished the idea of extension from its unknown cause.
On the one hand, Shepherd holds that extension can only apply to objects considered as causes, for it is as causes that they take up space and move. Ideas, on the other hand, neither move nor take up space, or we would be left with the ridiculous position that the idea of a fat man is itself fat.
Shepherd, in defense of this claim, gives a fresh defense of her causal realism.While it is true that the mind perceives internal changes to its own states, it nevertheless reasons to the existence of external unperceived causes of these changes.