Don Garrett

Although a great deal has been written about Hume’s epistemic skepticism in A Treatise of Human Nature, it is An Enquiry concerning Human Understanding that contains his final comprehensive treatment of the topic, and it is this treatment that his later references to skepticism most closely echo. In Section 12 of the Enquiry, Hume surveys ten skeptical arguments directed against the veracity of one or another species of “evidence”: the evidence of the senses, the evidence of demonstrative (i.e., “abstract”) reasoning, and the evidence of non-demonstrative (i.e., “moral”) reasoning. Many have interpreted the Hume of the Enquiry as a radical epistemic skeptic because, after surveying these arguments, he concludes that some of them (namely, the more “philosophical” and “profound” among them) can have no other tendency than to show the whimsical condition of mankind, who must act and reason and believe; though they are not able, by their most diligent enquiry, to satisfy themselves concerning the foundation of these operations, or to remove the objections, which may be raised against them. (EHU 12.23) Yet although he in no way retracts this description, it does not constitute his final overall judgment on skepticism in the Enquiry. Instead, he immediately goes on to begin the third and final part of Section 12 as follows: There is, indeed, a more mitigated scepticism or ACADEMICAL philosophy, which may be both durable and useful, and which may, in part, be the result of this PYRRHONISM, or excessive scepticism, when its undistinguished doubts are, in some measure, corrected by common sense and reflection. (EHU 12.24; see also DNR 1.11) He then goes on to close the book by classifying many “proper objects of science and enquiry.” (EHU 12.26–29) This passage raises at least four pressing interpretive questions. These are: Q1. In what respect or respects is Pyrrhonian skepticism excessive? Q2. How are Pyrrhonian skeptical doubts undistinguished? Q3. In what measure do common sense and reflection correct Pyrrhonian skeptical doubts to produce mitigated skepticism? Q4. Why is the mitigated skepticism that results in part from Pyrrhonism a correction of its doubts? In order to answer these questions, it is necessary first to understand a number of theses that Hume accepts about four key phenomena he invokes in Enquiry 12: evidence, correction, skepticism, and common sense and reflection. The first four sections of the essay explain the meaning and grounds of these theses, noting along the way a number of respects in which the Enquiry’s treatment of skepticism differs from—and is often superior to—that of the Treatise. The fifth section deploys these theses to answer the four pressing questions about Hume’s final verdict on skepticism. The final section concludes that Hume is a mitigated epistemic skeptic but not a radical epistemic skeptic in the Enquiry, for he holds that many of our beliefs have a very considerable degree of objective evidence.

Although Hume did not thematize the value of humanity in the way that Kant did, he says enough about humanity and value in his writings for us to determine his likely views about a number of different questions concerning it. Kant, a moral rationalist and a moral antinaturalist, holds that the value of humanity is fundamentally moral value that is both grounded in and recognized by the rationality, not the sensibility, of human beings as noumenally free agents outside of nature. Hume, the moral antirationalist and moral naturalist, holds that humanity, as a part of nature, has many kinds of value—including moral value—that are both metaphysically and epistemologically determined by either _sentiment_ or _passion_, as assisted by reason, and which typically also depend for their possession on having both reason and sensibility.

The sixth chapter of _ERCE_ begins by distinguishing and criticizing six different and mutually incompatible definitions of ‘life’ that Shepherd identifies in William Lawrence’s _Lectures on Physiology, Zoology, and the Natural History of Man_. It then provides Shepherd’s own positive view of life, as a quality originating ultimately from God and mixing with matter to produce a living thing. In this respect, it is analogous to a spark that must be added to combustible materials in order to produce an ongoing fire. Next, it offers eight propositions in summary of the account of causation provided in previous chapters of _An Essay upon the Relation of Cause and Effect_, and it further diagnoses Lawrence’s alleged errors about that relation. It concludes by describing the most fundamental principles of _ERCE_ as the “true foundations of scientific research, practical knowledge, and belief in a creating and presiding Deity.”

The fifth chapter of _ERCE_ criticizes William Lawrence’s materialism in his _Lectures on Physiology, Zoology, and the Natural History of Man_, which he supports by appeal to the Humean account of causation found in the work of Thomas Brown. It focuses especially of Lawrence’s treatment of the “necessary connexion” between “irritability” and “living muscular fibres” and between “sensibility” and “living nervous fibres.” The chapter argues that Lawrence fails to recognize the need for separate qualities of _life_ and _mind_ because he fails to distinguish between two possible relations that can be meant by the term ‘necessary connexion’, one of them merely verbal and the other metaphysical and causal. Shepherd traces Lawrence’s alleged errors to his acceptance of the central features of Thomas Brown’s treatment of causation. Foremost among these is Brown’s definition of ‘cause’ as a relation essentially involving temporal antecedence and consequence between distinct objects.

The fourth chapter of _ERCE_ discusses Thomas Brown’s _Observations on the Nature and Tendency of the Doctrine of Mr. Hume, concerning the Relation of Cause and Effect_. First, it disputes Brown’s Humean definition of ‘cause’ as requiring temporal succession. Second, it discusses and assesses each of the five Humean propositions about the epistemology of the relation of cause and effect that provide a central focus of Brown’s book. Third, it argues, against Brown, that Hume’s account of the origin of the idea of “power” in the operation of custom rather than reason cannot avoid atheistic implications. Furthermore, it concludes, Brown’s own conception of the idea of “power,” as the consequence of an unavoidable instinctive belief whose truth cannot be established by reason, is fundamentally no better than Hume’s in this respect.

The third chapter of _ERCE_ seeks to show, against Hume, that “_Custom and Habit_ alone are not our guides; but chiefly reason, for the regulation of our expectations in ordinary life.” This requires explaining why we expect apparently similar objects to behave similarly. The solution to this practical problem has two parts. First, Shepherd argues, we can demonstrate from the Causal Likeness Principle that if two apparently similar objects were produced entirely by the union of exactly similar contributing causes, then those objects are exactly similar and hence will have exactly similar effects. Secondly, by investigating the observable similarities of those contributing causes, and the observable similarities of _their_ contributing causes, and so on, we can render it highly _probable_ that the objects were in fact produced by exactly similar causes and so _will_ have exactly similar effects.

Following a preface explaining Shepherd’s reasons for writing, the introductory chapter of _ERCE_ aims to set out Hume’s position concerning “the necessary connexion of cause and effect” largely in his own words. It begins with his views as presented in his _A Treatise of Human Nature_ and then cites _An Enquiry concerning Human Understanding_ to show that he holds the same doctrines in that work. Hume’s “material proposition” is that “Nature may be conceived to alter her course, without a contradiction.” The chapter seeks to show that both works depend on the thesis, stated only in the _Treatise_, that “it is neither intuitively nor demonstrably certain [that] whatever begins to exist must have a cause of existence.” It is important to refute this thesis, she concludes, because it leads to the dangerous atheistic consequence that there is no “necessity of a great first Cause, and ‘productive principle’ of all things.”

The second chapter of _ERCE_ aims to show, against Hume, that “_Reason_, not _fancy_ [i.e., the imagination] and ‘custom’ leads us to the knowledge” of the central principle (now often called Shepherd’s “Causal Principle”) that “everything which begins to exist must have a Cause.” The chapter provides an argument in defense of that principle and then a further argument from it to the crucial principle (now often called Shepherd’s “Causal Likeness Principle”) that “_similar causes_ must necessarily produce _similar effects._” It goes on to describes the source of the idea of necessary connection and outlines her own positive theory of relation of cause and effect. Next, it provides Shepherd’s own positive definitions of ‘cause’, ‘necessary connexion’, and ‘power’, and raises objections to Hume’s definitions of cause’. Finally, it seeks to establish her “Uniformity Principle”: “Nature cannot be supposed to alter her Course without a contradiction in terms.”

The editor’s introduction outlines and explains Mary Shepherd’s life and writings, focusing especially on those collected in this volume: _An Essay upon the Relation of Cause and Effect_, the two essays published in 1828, and her letters. It details the events that led her to write (including the so-called Leslie Affair of 1805 in Edinburgh and her correspondence with John Fearn). It also provides essential background information about the three figures whose philosophical views the _Essay_ chiefly criticizes: David Hume, Thomas Brown, and William Lawrence. It features substantive chapter-by-chapter analyses of the aims, arguments, and conclusions of that work. Finally, it provides information about Shepherd’s correspondents: Charles Babbage, William Whewell, and Robert Blakey.

Hume’s account of the idea of self is highly distinctive but not fully elaborated. The first section of this chapter describes some of the most important roles that the idea of self plays in Hume’s _Treatise_, and it highlights three questions that naturally arise from this description. The second section describes Hume’s rejection of the doctrines of some philosophers about the idea of self in favor of his own contrasting approach, and it highlights five further questions that naturally arise from this description. The third section explains and elaborates Hume’s positive theory of the nature and origin of the idea of self. The fourth section uses this elaborated theory to answer the eight questions raised in the first two sections. The final section comments briefly on the origins of Hume’s account of the idea of self and on the significance of its absence from his later works.

This chapter seeks to establish (1) that Spinoza accepts the legitimacy of many teleological explanations; (2) that in two important respects, Leibniz's view of teleology is not more, and perhaps even less, Aristotleian than Descartes's; and (3) that among Descartes, Spinoza, and Leibniz, it is Spinoza who holds the view of teleology closest to that of Aristotle. The arguments for (1) derive from examinations of Spinoza's doctrine of _conatus_, critical analysis of Jonathan Bennett's proposed grounds for interpreting Spinoza as denying all teleology, and the application of Spinoza's distinction of three kinds of knowledge to the distinction between mechanistic and teleological explanation. The arguments for (2) and (3) are based on an examination of the answers given by Aristotle, Descartes, Leibniz, and Spinoza to four basic questions about the nature and range of teleology and teleological explanation. These questions concern the dependence of teleology on thought, the relation of teleology to divine will or purpose, the existence of “sub‐human” teleology, and the role of teleological explanation in natural philosophy.

What problem led to Hume's famous second thoughts about his own discussion of personal identity? There is no scholarly consensus, but one of the best-known explanations was offered by Barry Stroud in his book _Hume_. This essay begins by deriving from the texts a set of criteria by which to judge proposed explanations. It then proceeds to distinguish and assess several types of approach, to defend Stroud's general approach against a recent objection, and to explain why Stroud's more specific explanation is promising but in need of further specification. Finally, it provides the needed specification by formulating three Humean doctrines concerning causation and location, describing some of the multiple unacceptable consequences their conjunction produces, and arguing that the resulting problem alone meets the criteria for a satisfactory explanation of Hume's second thoughts.

Mary Shepherd concludes An Essay upon the Relation of Cause and Effect – described in its subtitle as ‘Controverting the Doctrine of Mr. Hume’ – by listing several principles about causation as ‘the only true foundation of scientific research, of practical knowledge, and of belief in a creating and presiding Deity’. As it happens, Hume accepts each of these principles, at least as formulated. He also agrees that they are foundational – at least for scientific research and practical knowledge – and he allows that they can be supported by reasoning. Shepherd and Hume disagree, however, about the particular reasoning by which they can be supported; the order in which they can be supported; the role played by custom or habit in that support; and the kind of necessity they express. The four parts of the present essay (1) outline and examine Shepherd's arguments for each of the three distinct foundational principles; (2) outline and examine Hume's contrasting arguments for those principles; (3) compare their differing approaches to providing epistemological foundations by means of these principles while highlighting some of the objections that might be made to each approach; and (4) offer brief concluding remarks about adjudicating the relative merits of the two approaches.

Recent years have witnessed an impressive and welcome groundswell of interest in the philosophy of Mary Shepherd. Although Antonia LoLordo's recent forty-eight-page Mary Shepherd in the Cambridge Elements series (Cambridge University Press, 2022) provides a useful overview, until now there has been no full-length book devoted entirely to Shepherd's philosophy. Deborah Boyle's Mary Shepherd: A Guide will assuredly not be the last such book, but it is an excellent and timely first. As its title indicates, Boyle's book is intended as a guide, and it succeeds admirably in its task. It can be studied with great profit by scholars already familiar with Shepherd's writings, but its careful organization and clarity of... Read More.

Mary Shepherd’s An Essay upon the Relation of Cause and Effect, first published in 1824, was a pioneering work in metaphysics and epistemology. Together with her 1827 Essays on the Perception of an External Universe, they make her one of the most important philosophers of her era. Although widely neglected by the history of philosophy in the decades after her death, her works have recently begun to attract the attention and sustained study they deserve. In the course of her writings, Shepherd offers trenchant and detailed rebuttals of the arguments and conclusions of many prominent predecessors—including George Berkeley, Thomas Reid, Dugald Stewart, Thomas Brown, William Lawrence, and especially David Hume—but she is no merely negative thinker. On the contrary, her critiques are always in the service of her own distinctive and highly original doctrines, which are of striking contemporary interest. Appearing two hundred years after its original publication, this is the first full modern edition of her first book, which presents and defends the theory of causation and scientific knowledge that constitutes the cornerstone of her entire philosophy. The edition includes an extensive introduction and scholarly notes throughout that provide historical and philosophical context while explaining the central ideas of the work. It also includes Shepherd’s two essays published in 1828 and all of her known letters—all but one of them published here for the first time—which shed significant additional light on her philosophical ideas.

William E. ("Ted") Morris and I co-edited Hume Studies from its first issue under the official auspices of the Hume Society (19.2, November 1993) through its Twenty-Fifth Anniversary Issue (26.1, April 2000). Our first issue featured papers by Annette C. Baier, Barry Stroud, Simon Blackburn, David Pears, and Antony E. Pitson from a conference that Elizabeth S. Radcliffe had organized at Santa Clara University.The exceptional design talent and skill of Linda Weiner Morris allowed us to introduce new typography, new dimensions, and a new cover design with that first issue. With the assistance of David Fate Norton, we replaced the portrait of Hume that had graced earlier issues with an image of Hume's own bookplate... Read More.