The Manifest Connection: Causation, Meaning, and David Hume

1. Introduction

exciting recent hume scholarship has challenged the traditional view that Hume's theory of meaning leads him to deny the very intelligibility or coherence of supposing that there are objective causal powers or intrinsic necessary connections between causally related entities. Influential recent interpretations have variously held that Hume himself accepted the existence of such powers and connections, that he was genuinely agnostic about them, or that he denied their existence while nonetheless holding it to be a perfectly coherent possibility, indeed one that we routinely (albeit mistakenly) think actual. In this paper I will argue against all three of these lines of interpretation and in favor of what I consider a neglected alternative: that Hume rejects the existence of objective necessary connections or causal powers as literally incoherent or meaningless, but on subtle and sophisticated semantic grounds, rather than simplistic ones. ¹ I find support for this semantic reading and against the alternatives not only in passages whose significance to the debate is widely appreciated, but also in Hume's discussions "Of Liberty and Necessity" and "Of the Immateriality of the Soul."

The claim that Hume is a causal realist ² (i.e., that he takes genuine causation to involve the operation of causal powers in objects themselves) has recently been defended by, among others, John Wright, ³ Donald Livingston, ⁴ Edward Craig, ⁵ and, in the most convincing detail, Galen Strawson. ⁶ According to Strawson, Hume is concerned to deny only that we have any knowledge or comprehension of the causal powers in objects. He holds that Hume offers a regularity theory of our knowledge or experience of causation, and that only the legacy of positivism leads us to mistake this for a regularity theory of causation as it is in itself. Strawson claims that Hume's unembarrassed references to "those powers and principles on which the influence of . . . objects entirely depends" (Enquiry 33) and "those powers and forces, on which [the] regular . . . succession of objects totally depends" (Enquiry 55) reveal that Hume himself believes that there are causal powers in objects, even though his skepticism prevents him from claiming to know that there are. ⁷ Strawson goes on to argue that this very skepticism prevents Hume from making any knowledge claim about how causation is in itself, including the claim that it is definitely just regular succession or that there is definitely not any such thing as objective causal power.

This latter contention has achieved a wide currency even among scholars who seek to refute the claim that Hume himself believed in such powers, swelling the ranks of those who take Hume to be truly agnostic about the existence of objective causal powers or necessary connections. Kenneth Winkler, ⁸ for example, mounts a thorough and convincing attack on the notion that Hume believed in objective causal powers, but he ultimately accepts Strawson's claim that skeptical modesty prevents Hume from denying that there are causal powers in objects, concluding instead that Hume merely "refuses to affirm" that there are. Similarly, Terence Penelhum argues that Hume cannot claim to know that there is no necessity in objects (on pain of dogmatism), insisting that his point must be instead "that we can recognize that our ascription of necessity is mere projection, hallowed by habit and not by right." ⁹ Simon Blackburn also rejects the thesis that Hume believes in objective necessity, but he claims that its supporters merely "misplace the stress" of Hume's argument and commit "an error of taste rather than an outright mistake," because he takes Hume's point to be that even if we can refer to regularity-transcending necessity or powers in objects, he is "utterly contemptuous of any kind of theorizing conducted in terms of such a thing." ¹⁰ The realist and agnostic camps, then, share an important interpretive thesis—that Hume's skepticism prevents him from denying that there...