Causation and Significance of the Natuarl/philosophical Relation Distinction in Treatise1.3.6

Causation and the Significance of the Natural/Philosophical Relation distinction in Treatise 1.3.6

The main aim of this paper is to explore why it is so important for Hume to define Ð''cause' as he does. I take up this question in order to shed light on the significance of the natural/philosophical relation (hereafter NPR) distinction, especially as it is used in Treatise 1.3.6. I argue that the NPR distinction allows Hume to dismiss conceptions of causation at odds with his own; it provides an instance of the normative nature of Hume's "science of man."

Treatise 1.3.6 is much studied in the context of debates over Hume's skepticism, his understanding of "reason," and what has become known as the problem of induction. In this paper, I largely side-step these debates, although I show that even if one thinks that there is no trace of Hume's skepticism in 1.3.6, the section has more bite than is recognized by those advocating the apparent, current scholarly consensus on the nature of Hume's naturalism. For a consequence of my analysis is that the NPR distinction -- in conjunction with an important corollary to the so-called copy principle -- is meant to undercut appeals to the authority of theories not founded on the "principles" of Hume's "science of human nature."

In order to illustrate my claims about Hume's account of causation, I contrast it with Newton's natural philosophy. Doing this has the nice consequence that it reinforces an argument that I have made elsewhere: that Hume's philosophy is, despite oft-repeated claims to the contrary, deeply at odds with Newton's and, of course, many other philosophers and natural philosophers. In this paper, I do not adjudicate between Hume and Newton.

Here follows a summary of this paper. First I provide an account of Hume's treatment of causation in Treatise 1.3.6 (II). Second I explain the indebtedness of the conceptual structure of Hume's analysis of causation to the pre-Newtonian Mechanical philosophy (III). Both sections contrast Hume's account of causation with various kinds of causes to be found in Newton's natural philosophy. Third, I briefly describe the copy principle in Hume (IV). I am then in position to use a Newtonian objection to Hume's treatment of causation to motivate my interpretation of Hume's deflationary conception of philosophic relations (V). My brief concluding remarks call attention to how the reading of Treatise 1.3.6 proposed here anticipates Hume's more explicit statements about his philosophic goals in EHU.

II: The Origin and Meaning of Causes

Hume's account of causality covers at least five related issues: 1) how we acquire an idea of cause; 2) what we mean by cause; 3) how we reason about causes; 4) whether causes are in the mind or in nature; 5) how we could infer the existence of causes. In this paper I am concerned with Hume's treatment of the first three issues. In this section, I summarize Hume's treatment of the first two issues, and present some evidence that Hume's account of causation is at odds with a non re-visionary account of Newton's natural philosophy. In order to avoid misunderstanding: for the sake of argument, I do not view this conflict between Hume and Newton as a problem for Hume. In section V, I explain Hume's response to a possible objection.

In the Treatise, Hume quite elegantly analyzes how Ð''our' notion of causality Ð'-- one applying to events that are contiguous, exhibit temporal priority of the cause, and have constant conÐ'¬junction (1.3, Sections 2, 6, and 15) Ð'-- is derived from experiencing constant conÐ'¬junction of objects that produce a union in the imagination (1.3.6.16). Hume's account is elegant beÐ'¬cause it is causal in its own terms, that is, his two definitions of the meaning of cause (Treatise, 1.3.14.31) are patterned on the chain of events that he thinks leads people to acquire the idea of cause. So Hume's treatment of the origin of the idea and the meaning of cause are tightly linked.

Hume's analysis is a useful first approximation and unification of what some of the austere "Moderns" (e.g., Descartes and especially Spinoza) tend to mean by Ð''causation.' In his hands, a redefined version of Aristotelian Ð''efficient causation' is the only kind of Ð''causation' available for use (see Hume's "first" corollary at Treatise 1.3.14.32). It rules out, for example, the "final causes" that Newton appeals to in his version of the probable argument from design in the "General Scholium" of the Principia: "We know [the Deity] only by his most wise and excellent contrivances of things, and final causes."

While Hume (cf. Treatise 1.3.15.6) and Newton (e.g., the Third Rule of Reasoning) both appeal to the authority of "experience," there are further serious tensions between Hume's account of causation and the contents of Newton's natural philosophy. The behavior of the moon in its orbit and that of, say, apples falling on the earth have the same cause: namely, the force of gravity, or weight, towards the earth. This conflicts with the contiguity requirement, which Hume considers "essential" to causation, (Treatise 1.3.2.6) although he drops the requirement in the first Enquiry. It was a notorious problem to make contiguity consistent with the universal nature of attraction. The most distant particles of the universe attract each other. More important, the acceleration produced by the exercise of a force is simultaneous with that exerciseÐ'--thus defying temporal priority. (Principia, Book III, Scholia to Propositions IV-V, and Theorems IV-V; see also my discussion of Newtonian interactive causes below). Hume explicitly attacks the possibiÐ'¬Ð'¬lity of an effect being simultaneous with its cause (Treatise, 1.3.2.7-8). This is not the place to explore more fully the tension between Newtonian simultaneous interactive causes and Hume's commitment to the temporal priority of the cause over the effect which, I think, is fundamental to Hume's understanding of causation.

Section III: Pre-Newtonian Mechanical and Newtonian Mechanical Causes

In this section I further investigate the differences between Hume's and Newton's conceptions of causation. To clarify my treatment of Hume, I introduce a distinction between Pre-Newtonian Mechanism and Newtonian Mechanisms.

It is the great virtue of Hume's analysis to make clear what several generations