The Two Scepticisms in Hume’s Treatise

THE TWO SCEPTICISMS IN HOME'S TREATISE MONG the many anomalies of Hume's thought one of the most striking is the contrast between the limited, philosophical scepticism which Hume set out to defend at the beginning of the Treatise and the radical scepticism which he was forced to admit at the end of the first book of the Treatise. In the first three parts of Book One (and more implicitly than explicitly in the second and third books) Hume is sceptical of all attempts to construct a rational metaphysics. He insists that custom and association alone explain our natural certitudes, and that any rational (i.e., strictly logical) explanation of them is foredoomed to failure. He tells us that we must accept our natural certitudes and be sceptical of any rational explanation of them. But in the fourth part of Book One Hume's argumentation leads him to a much different conclusion; there he finds that, as a philosopher, he must reject even our natural certitudes.1 For years this second position, that of radical scepticism, was considered the essential element of Hume's thought. With this as their premise, Hume's critics suppressed the positive elements of the first position, especially his trust in our natural judgments-the naturalism which has been so much emphasized in recent years/ and found that the Hume who. remained was easily refuted. He was the complete sceptic, who used reason to deny reason, and built up complex arguments to show that 1 Hume himself was aware of the anomaly of this position. Early in part four of the first book of the Treatise he tells us: " I begun this subject with premising that we ought to have an implicit faith in our senses. . . . But to be ingenuous, I feel myself at present ... more inclin'd to repose no faith at all in my senses...." I, iv, 2 (T, 217) [I, iv, :2 =Treatise, Book One, Part Four, Section Two; T =the Selby-Bigge edition of the Treatise.] • Kemp Smith is most responsible for the re-interpretation of Hume. His articles, "The Naturalism of Hume," Mind, N. S. XIV (1905), 149-73 and 33.5-347 and his The Philosophy of David flume (Edinburgh and London, 1941) are required reading for any serious student of Hume. 419 JAMES V. :MCGLYNN no arguments are valid. Convinced that this was the real Hume, the critics dismissed everything else in his writings as inconsistency or as the clever dissembling of a revolutionary who preferred to tone down his statements rather than enrage popular opinion. Recent study of Hume has seen that this simplistic view does not do justice to the complexity of Hume's thought, and various attempts have been made to re-evaluate Hume on the basis of the positive as well as the negative elements of the Treatise and Enquiry.8 But although this revaluation has led to a discussion of the contrasts inHume's thought, most of the work done on Hume's twofold scepticism has considered the relations between the two fully developed theories and the possibility or impossibility of reconciling the two. Not enough attention has been paid to the inner development of Hume's thought and to the interesting problem of why Hume himself in the fourth part of Book One of the Treatise felt obliged to abandon his naturalism and accept a much more radical scepticism. It is the purpose of this study to show that an investigation of this problem of why Hume himself passed from one scepticism to the other can throw much light on the nature of the Treatise itself and can enable us to distinguish a number of separate questions which Hume failed to distinguish. When we have sorted out these questions, we will be able to point out the source of a series of confusions which forced Hume to change the original question and pose a new problem which never would have arisen had he not abandoned his initial design. The key to the solution of this problem lies in Hume's distinction between knowledge and belief. This is the thread which goes through the first book of the Treatise, and it is Hume...