I’ve been pouring over Locke’s Essay. One reason for doing so is that while straight-up passivists are usually (either expressly or deep down) Humeans, less overtly passivist positions in/elements of the contemporary powers-related discussion are, in key respects, recognizably Lockean. But more on the nature of the developing literature another time. For now I just want to say, for the record – though I’m sure that I am not the first to come to this conclusion – that Locke’s own account of what he calls a power (and those aspects of his metaphysics to which it is related, no pun intended) is fraught with problems.
Locke says that a power is a relation. (Notice that that phrase rolls off of the tongue, but that it is nevertheless not at all clear that that is what a power is.) A relation, in turn, is an idea — a “complex idea,” Locke says. Unlike a complex idea such as that of a substance with properties, which just is an amalgam of (simpler) ideas, a relation is the idea of there being a connection between two (or more) ideas, be those ideas simple or not. The mind, Locke says, can bring (ideas of) things together, considering them jointly.
Okay, good. So relations are ideas, not objectively real entities, or real features of bodies. And note that we don’t yet know just what the content of the idea “power” is; we just know that it’s the kind of composite idea that involves bringing ideas together but without amalgamating them into a unity, as one does when one forms the complex idea that is that of a substance of one kind or another.
Hold that thought.
Now let’s register some other things that Locke says. (1) Locke says that material bodies have a small number of properties that really do inhere in them, or can properly be said to be had by them. One of these is motion. (2) In addition to having a small number of real or primary qualities, as Locke calls them, material bodies also, according to Locke, have (i) secondary qualities and <wait for it> (ii) powers. Only, since properly speaking they don’t actually have these features, not really (I will remind us why in a minute), it would be more accurate to say that, in Locke’s view, material bodies “have” – i.e., appear, to us, to have – the properties (or apparent properties) that he calls secondary qualities and powers.
Moving on. (3) Re: (i), what “secondary qualities” – i.e., properties that things only appear to have – what secondary properties really are, says Locke, are ideas in the mind of a human subject. “Whiteness” is a real live idea, but it is not actually a property had by my tea mug. This said, (4) even though my mug does not have a property of “whiteness,” the idea of “whiteness” is caused to be in my mind by the properties that my mug does have. (5) Re: (ii), I’ve already said what a “power” is, according to Locke — or at least enough to make it clear that it is not something that is actually had by an object to which it might nonetheless be ascribed.
Here is where the trouble starts. Or, at least, the trouble that I want to talk about now.
Let’s try to fill out the rest of what Locke says about what a power is. What is it to cause something, for Locke? “Cause and effect” is an instance of just that type of idea that Locke calls a relation — again, the bringing together of two ideas, by the mind, into a complex idea in which the component ideas are not amalgamated but rather are considered jointly in one way or another. In this case (unlike the case of the relation “taller than,” say), the way in which the relata are considered jointly is that one is thought to be the source of alteration, as Locke puts it, in the other. Thus: (6) “a thing being the source of alteration in another thing” turns out to be the content of Locke’s idea of an active power.
But now we really have a problem. Actually more than one. Locke says that we get the complex idea “power” from two sources. We get it from reflection on the operation of our mind, and we get it – though less distinctly – from our experience of external material objects. (Indeed, Locke opines in Bk. II, ch. 21 that it “may well be” that the idea “power” is actually a simple idea, not (after all) a complex idea. This matters in some ways, though being a simple idea is not enough to tell us that the idea refers to an actual property of things; “white” is a simple idea, and yet, inasmuch as it is a secondary quality, it doesn’t refer to a property of “whiteness” that is or could be had by anything.)
Here are at least some of the problems, as I see them.
One problem involves circularity. First, insofar as we take Locke at his word, and assume that “cause and effect” is a relation, then for a given cause x to be the source of alteration or change in y can only be for the idea that represents x conceptually to be brought together, by the mind, with the idea that represents y. Brought together … how? In a way that involves the idea of “being the source of alteration.” But if that is so then we are back where we began. Moreover, the very ideas that are being related in the “source of alteration”-way, are themselves said by Locke to be “caused” by the real or primary qualities of things. This is so (according to Locke) whether the ideas in question are of primary qualities or of (“of”) secondary qualities. But for the moment let’s attend only to the case of secondary qualities being ideas that are caused by real or primary properties. Here too, if we assume Locke’s definition of “cause,” what is actually happening when the mug’s real or primary qualities cause my idea of whiteness is that the idea of “whiteness” is being related, by me, to some one or number of the mug’s real or primary qualities. But this requires us to posit the very idea of whiteness the genesis of which we are supposedly explaining.
We can plug both of these points back into Locke’s claim that in addition to secondary qualities, things have (“have”) powers (i.e., can be sources of alteration), in order to plot out what such a claim can and cannot actually amount to ontologically. (Of course, the same circularity will also figure in the simpler case of real or primary qualities causing our ideas such qualities.
A different problem involves coherence. There is really no question, it seems to me, but that Locke thinks that active mental powers, at least, involve the actual doing of something. The only real property of things to which the idea of “doing” could refer is that of motion (or being in motion). But Locke’s discussion of active mental powers clearly involves activity that does not reduce to, and cannot be reduced to, mere motion. Of course, we can deny that either of Locke’s broad categories of powers, mental or physical, do refer to actual doing. In that case, the mental activity of “bringing together” will simply add an additional layer of circularity, to the conceptual scenario set out above.
These points about Locke are interesting for their own sake, for some of us. But I think that they are worth working through even if one doesn’t find them inherently interesting, just as mental exercise for thinking well about powers.