## Michael Lynch’s _Truth as One and Many_ on Domain Logical Pluralism

February 26, 2018

~1500 words, ~1200 w/o footnotes

Recently I was looking through Lynch’s book on truth, Truth as One and Many. I was interested in its chapter-long discussion of domain-specific logical pluralism. There he writes about the natural idea that different logics should apply in different domains: say, intuitionism in moral or mathematical domains, but classical logic when talking about physical objects.

I wanted to see what he thought about what we ought to do in the case of sentences mixed across domains. For example, a disjunction might have its first disjunct from one domain and one logic but its second from another. (The logics might disagree about how to handle $\lor$, after all.)

Here’s his idea (and, what this whole post is about):

Modest
where a compound proposition or inference contains propositions from distinct domains, the default governing logic is that of the compound or inference’s weakest member. (100)

## Jumpstarting the Blog: Objecting to Sider’s Objectivism

June 27, 2012

Given that it’s been over a year since we’ve had any posts, I’ve decided to try to jumpstart the blog again. Here goes…

While reading Sider’s Writing the Book of the World, I noticed a strange dialectic circularity. One of Sider’s main theses is that structure is objective: it’s ‘out there in the world’ in some metaphysically heavy sense. But, Sider then goes on to give an account of objectivity in terms of structure. Given this circularity, it’s possible to find a reductio.

Sider claims that structure is not subjective (i.e. structure is objective). I take this to mean that sentences about structure are not subjective. Without loss of generality, let’s take the following sentence about structure:

(S): ‘being negatively charged’ is structural

Sider wants to claim:

(O): (S) is not subjective

He goes on to give the following account of subjectivity: “A sentence is subjective…if and only if it’s truth-value depends on which of a range of equally joint carving candidates is meant by some term in the sentence, where the candidate that we in fact mean was selected in a way that is not arbitrary, but reflects something important about us, such as our values” (59). Combining this account of subjectivity with (O) gives us:

(O’): It’s not the case that the truth value of (S) depends on which of a range of equally joint carving candidates is meant by some term in (S), where the candidate that we in fact mean was selected in a way that is not arbitrary, but reflects something important about us, such as our values.

This roughly amounts to saying that in order for facts about structure to be objective, they must ‘carve at the joints’ — in other words, facts about structure must themselves be structural. But that’s a condition that far too easy to meet. For instance, take a simple expressivist view of structure. Roughly, to say ”being negatively charged’ is structural’ is simply to express some mental attitude A towards ‘being negatively charged’. I think we can all agree that, pretheoretically, this is a subjective account of structure. But, if Sider’s account of subjectivity is correct, an expressivist account of structure is consistent with the claim that (S) is objective. Accepting (O’) amounts to expressing attitude A towards ‘is structural’; this is all we need to accept (O’), because the terms in (S) do not have ‘a range of equally joint carving candidates’ — by our own lights, ‘structural’ is joint-carving. So, either Sider must reject his account of objectivity or accept that expressivism about structure is consistent with structure being objective. I take it that he will choose the former.

Thoughts?

## David Lewis + Kit Fine = Weirdness

May 24, 2011

David Lewis thinks that properties are just sets of possible individuals. SEP: “Lewis argues that for any set of actual and possible objects (fundamental or not), there is a property, namely the property an object has just in case it is a member of the given set.”

Kit Fine thinks that essence is an asymmetrical relationship. Specifically, it is an asymmetrical relationship between a set and its constituent(s). Although Socrates is essential to the singleton set {Socrates}, the set is not essential to Socrates. “It is no part of the essence of Socrates to belong to the singleton.” (“Essence and Modality“)

Suppose you accept both. Then no individual has any property essentially. After all, a property is a set, and it is not part of the essence of any individual to belong to any set. Moreover, every property has its bearers essentially. After all, constituents of a set are essential to that set. On the face of it, that is pretty weird.

Ways to get out: (1) Most obviously, don’t put Lewis and Fine together. (2) Clarify what Fine says, so that the essence relationships hold for some sets but not others. (3) Clarify what Lewis says, so properties aren’t just sets, but in some sense correspond to them. Both (2) and (3) look ad hoc to me, so perhaps the weirdness can count as an incompatibility result between Lewis and Fine?

## Most Expensive Parking Ever

March 17, 2011

Ann Arbor, like most cities, is currently struggling to pay the bills. It’s rare that metaphysics can help with these problems, but this case is different.

The city has recently raised the parking rates: It used to cost \$1 per hour to park next to the city library. Now the rate is published like this:

60 cents per half hour for the first three hours, and 70 cents per half hour and part thereof after the first three hours.

Given the number of parts of half hours, it seems pretty steep to me.

## Color-judgment expressivism?

March 18, 2009

Hey guys,

I don’t know too much about the philosophy of color, except for what you learn from examples people use in discussions about other topics. I’ve noticed that some people, to take one example, think that we should be error theorists about color: we falsely believe that surfaces have these mind-independent color features that they don’t really have, and therefore our color-judgments attributing these properties to surfaces are all systematically erroneous.  This, if I am not mistaken, is Velleman’s view. He brings this up in a discussion about whether people’s belief in free will is some kind of systematic illusion of a similar sort.  Other people, like Gibbard, think that an error-theory about color-judgments is too extreme; we should not attribute systematic errors to the folk unless no other, friendlier theory is available.  One type of theory of a friendlier sort takes color-judgments to be judgments about dispositional properties: we judge things to be such that they tend to look a certain way to people.   But, what are some other possible views?

Here’s what I am specifically interested in knowing: do you guys know if any philosophers have given expressivist views about color judgments?  The idea would be something like this.  In saying, for example, “the sky is blue” what people are doing is expressing their mental state of seeing the sky as blue.  Now, what is their seeing it as blue supposed to mean here?  Well, perhaps I would have done better to say something like “they express their mental state of its looking a certain particular way to them”.  So, the state of judging something to have a certain color is closely tied, on this view, to the state of something looking/appearing a certain way to you.  And, if you say that the thing has the color in question, then you are expressing this state of mind, rather than reporting it.  (This, by the way, seems right: in calling something blue it seems better to say that I am expressing my state of mind of seeing it as blue than to say that I report its looking to blue to me.) Read the rest of this entry »

## Counterfactual-possibility

February 12, 2009

So I’ve been thinking about this objection I made to the Possible Worlds account of counterfactuals as an undergraduate, and I’m curious whether anyone has read something which deals with this problem (or whether anyone has a rough-and-ready rejoinder).

The objection goes like this: Possible Worlds Semantics (PWS) claims to give an account both of our notion of counterfactual dependence and our notion of possibility.  These are, roughly, the notions we express with the English constructions “If…had been the case, then…would have been the case,” and “It might/could be/have been the case that…”  PWS explicates these notions by saying that the former is true iff the closest world (on some contextually-defined similarity metric) in which the antecedent is true is a world where the consequent is true also.  The later is true iff there is some world accessible to the world of evaluation at which ‘…’ is true.

However, things seem to go screwy when we stick these two notions together.   Read the rest of this entry »

## Time Travelers and Their Temporal Parts

September 12, 2008

In Four-Dimensionalism, Ted Sider gives the following definition of a temporal part (p. 59):

x is an instantaneous temporal part of y at instant t =df (1) x exists at t, but only at, t; (2) x is part of y at t; and (3) x overlaps at t everything that is part of y at t.

I am a little puzzled about how to apply this definition to temporal parts of time travelers. Following Lewis, let’s distinguish external time (physical, objective) and personal time (subjective, “inner”). Intuitively, I think that different instants of personal time correspond to different temporal parts. I will explain why I believe that this intuition is incompatible with Sider’s definition of a temporal part, and it would be great if someone could tell me whether I am right.