Hume Studies

Hume's Argument Concerning the Idea of Existence John Bricke In"Hume on the IdeaofExistence"1Phillip Cumminsoffers anintricate and intriguing analysis of Hume's brief argument, at Treatise 1.2.6, concerning the idea ofexistence, an analysis that is, one wants to say, surely right on many of the essentials. He says relatively little, however, about a number of more preliminary matters, matters pertinent to the first of the several components he distinguishes in Hume's argument. I propose to focus on these preliminaries. Doing so will suggest a more direct route to Hume's conclusions than the one Cummins traces. My representation of Hume's argument, just as Cummins', makes the notion of separability central. But my representation ofwhat I call Hume's Basic Premise eliminates the need for the problematic premise m on which Cummins has Hume's argument turn, and so it eliminates any need for the argument components—6A and 6B—that Cummins has Hume offer in m's support.2 Hume argues from some claim or other about perceptions and existence—his Basic Premise—to the rejection of one philosophical theory (Cummins calls it the Distinctness Alternative, or DA) and the endorsement ofanother. The Basic Premise concerns both impressions and ideas. It concerns all impressions and ideas, or at least all those "of which we have any consciousness or memory."3 The universally quantified Basic Premise is also, I suggest, a biconditional, one suited to be used in the proof of the biconditional that is the constructive conclusion to Hume'sargument("Anyidea we please toform is the idea ofa being; and theidea ofabeingis anyidea we please toform" [T 67]). On the reasonable assumption that Hume views his constructive conclusion as a necessarytruththereisalsoreason toassume the Basic Premise is offered as a necessary truth. We may take it, too, that the BasicPremiseis onethatHume andhisopponentareassumedtoshare: the controversy concerns not the Basic Premise but its philosophical elucidation. Given this characterization ofits structure and status, what is the Basic Premise's content? Of course it has to do with impressions and ideas, and with existence, butjust how do they enter in? One source of difficultyhere is thefactthatHume mentions avarietyofpsychological attitudes towards the existence of something or other, and it is not Volume XVII Number 2 161 JOHN BRICKE immediately clear what role, if any, each of the several attitudes is designed to play in his argument. (He writes of something's being "conceiv"d as existent," of "attributing existence," of "assurance of being" [T 66], ofwhat "we believe tobe existent" [T 67].) Another source is the fact that he writes not only ofattitudes towards the existence of something or another but also of the actual existence of those things, whatever they be: "every object, that is presented, must necessarily be existent" (T 67). (In writing this he raises, perhaps, the troublesome spectre ofnecessary existence.) A third source ofdifficulty concerns the impressions and ideas themselves. How are they to be understood? Is it their existence that is in question? How are they implicated in the various attitudes Hume mentions? Decisions on these matters of content must affect the interpretation not only ofthe Basic Premise but also ofthe Derivation Principle4 and the Separability Principle5 that, together with the Basic Premise, constitute the heart of Hume's argument. It will encourage clarity ifwe take Hume's terms "impression" and "idea" narrowly. Ideas, as here understood, are neither concepts nor exercises of concepts; they are impression-like entities of a sort essential, ifHume is right, to the exercise ofconcepts. They,just as the impressions they resemble, may be said to be red or blue, round or square—more abstractly, to be F. To avoid assuming that these reified perceptions play an essential role in Hume's argument, however, let us introduce a more neutral notion, that of having an experience (including having an ideational experience6) with an experiential content. On this usage, one can have an experience as ofan F, or as of an object that is F, the "as of locution being used to introduce the experience's experiential content. Having such an experience does not entail the existence of an object that is F. Nor does having such an experience (whether or...