Thursday, June 12, 2008

yet another surprise from Leibniz

There is a funny route from Leibniz’s doctrine about subject-predicate containment to anti-essentialism (that sounds ludicrous at first, but it gets clearer when I explain what kind of anti-essentialism I mean).

Leibniz writes, “In every true affirmative proposition, whether necessary or contingent, universal or particular, the notion of the predicate is in some way included in that of the subject (FW 111-2).”

As he develops this line of thought, he ends up meaning something much stronger and controversial: (a) the complete concept of any substance S includes all the predicates P true of it; (b) the only way that one can refer to S is through its complete concept; and (c) for each S there is and can only be one complete concept (tantamount to saying that no two complete concepts do or could refer to the same thing).

This creates a prima facie problem with contingency itself. It seems to imply that if one utters truly that S is P it follows that S could not have been not-P. The “could not” is modally serious — implying that P is essential to S — implying that everything true of S is essential to S.

His famous example is the biblical character Judas. In Discourse on Metaphysics 30, he writes, “Why is it that this man will assuredly commit this sin? The reply is easy: otherwise he would not be this man.” What follows the “otherwise” Leibniz takes to be conceptually impossible — in effect, a violation of the conditions of identity.

(One could try to use contemporary counterfactual logic to claim that perhaps Judas in near worlds consistently commits the sin in question, but in worlds farther away he does not. The problem in Leibniz’s context is that this runs into constraint (c) above.)

That this really does threaten contingency is something that Leibniz tries to stave off with a strange analysis of contingency. He writes of contingent truths, “though the predicate inheres in the subject, we can never demonstrate this, nor can the proposition ever be reduced to an equation or an identity, but the analysis proceeds to infinity, only God being able to see (not the of the analysis, indeed, for there is no end, but) the nexus of terms or the inclusion of the predicate in the subject, since he sees everything that is in the series (L 265).”

This really doesn’t appear to have anything to do with whether in the nature of the case there is a distinction between features of substances that are essential or not, and this has been pointed out by many commentators on Leibniz.

He seems to be in a pretty tough spot, and this is what I meant earlier when I said of Leibniz that ironically he’s an anti-essentialist... in this specific sense: to the degree that essentialism, to be an interesting philosophical doctrine, demarcates essential properties from properties that aren’t, Leibniz doesn’t appear to have a way of marking that difference, because his philosophy implies that all properties of any S are essential to S.

John Locke, Leibniz’s great foil, is also agreed in anti-essentialism, but in the completely opposite articulation — viz., no properties, in the nature of the case, are essential to any S qua res.

3 comments:

tpy said...

I think that's why it's helpful to label Leibniz a "super-essentialist" - to separate him out from folks like Locke.

But there is another way we could go. There's a distinction among the scholastics between a thing's essence and its proprium. It's proprium are the properties that follow necessarily from its essence. Since the essence is necessary, so is the proprium. But this just goes to show that the essential properties are a (at least sometimes proper) part of the necessary properties.

Contemporary philosophers make no such distinction with regard to essential properties, but I kind of like this one. To use the standard example, human beings are necessarily risible (able to smile/laugh), but this is not an essential property, although it does follow from the essential properties (I guess from rationality somehow).

The problem is, this move should be open to a Scholastic-lover like Leibniz, but since (e.g., in Primary Truths) he seems to treat predicate-in-subject as equivalent to properties-in-thing, he apparently doesn't want it.

Dan said...

Tim,

Thanks for your comment.

I’m aware of the essentia-propria distinction, and it does help clarify distinctions among kinds of properties, though I suspect it has much more mileage in contexts where the concept of a kind-defining species has more philosophical work to do.

However, in this context, even if we grant this distinction, I’m still not clear about something.

I am not able to see that it does anything to alleviate the mess that Leibniz appears to be in — viz., being unable to justifiably claim of any given P that it is NOT essential or necessary to S. Any predication of any property (whether it be called essential, propria, or accidental) is strictly implied by the complete concept of S, combined with the restrictions (b) and (c) outlined in the original post.

Regarding the terminological difference between thinking of Leibniz as a “super-essentialist” or “anti-essentialist,” I guess I kind of think of these two descriptions as flip sides of the same coin when it comes to Leibniz. Qua “super-essentialist,” Leibniz takes all properties to be essential or necessary (his protestation that he endorses contingency notwithstanding). Qua “anti-essentialist,” Leibniz (his protestation notwithstanding) doesn’t really have the materials to make a clean distinction between essential and accidental properties and as such denies one of the most interesting things about the semantics of essentialism (i.e., that there IS a difference).

tpy said...

Dan,

Re: super-essentialism vs. anti-essentialism
I agree that we reach a point where in some respects super-essentialism is virtually indistinguishable from anti-essentialism. (Gosh, that sounds an awful lot like anti-essentialist thinking!) But there is at least one important difference. Consider Leibniz's question, "Could Judas not have betrayed Jesus?" Leibniz must say no, since Judas essentially betrayed Jesus, just as everything Judas did is essential to him. The anti-essentialist can say yes, provided we're not viewing Locke under a description that makes us say something like "the person who betrayed Jesus did not betray Jesus."

Re: the main worry
But back to your worry: "the mess that Leibniz appears to be in — viz., being unable to justifiably claim of any given P that it is NOT essential or necessary to S." You'll have to clarify what the mess here is exactly. Let me offer one problem you might have in mind and some help for Leibniz.

Perhaps the worry is that *of course* some of my properties (like wearing an orange shirt today) isn't essential to me, but if Leibniz is right, then it is essential to me. So we go modus tollens.

A partial solution: Although I don't think Leibniz makes use of this like he could, a Leibnizian could be a strict super-essentialist and deny that Ceasar or Judas or TPY exists in any world but this one, while also maintaining that when we are talking or thinking loosely ("with the vulgar" as Berkeley says) we can think of Lewis-style counterparts that are very similar to us that ground our loose way of speaking. So now, I do not have the property "could have worn a green shirt today" but we often think/talk this way because there is a nearby world where TPY* wears a green shirt. There's no rigid designation going on, and as philosophers we probably shouldn't talk this way, but we can explain our intuitions this way.

That's at least partly how I make Leibniz more plausible (to myself) on this matter. In strictness: superessentialism with rigid designation. Thinking loosely and explaining intuitions: counterpart theory.

Re: essence vs. proprium
I do think a distinction like this is needed by Leibniz in his account of miracles. For Leibniz, a miracle goes beyond the "natural" ability of a thing. But of course, that the miracle is performed is part of the concept of that thing, and is thus necessary for it to be it. So there must be a proper subset of a thing's necessary properties that are more central or important or "natural" to a thing. So there does seem to be some need for Leibniz to appeal to a distinction like that between and essentia and propria.