Tooley on Laws of Nature and Counterfactual Support

So I was looking over Dan’s reconstruction of Tooley’s argument below, and I’m still somewhat worried about its validity.

Dan mentioned that I thought there might be some funny business with premises (3) and (10) (on his first reconstruction):

(3) It is a nomological truth that all salt, when in water, dissolves.

(10) It is true that if this piece of salt were in water and were not dissolving, it would not be in the vicinity of a piece of gold.

Dan’s certainly right that there’s no straight-up contradiction here (like there would be if (10) was stating a material conditional).  However, something still feels very odd about the line of argumentation being taken.  What originally bothered me was the fact that, in (10), we are using a putative law to support a counterfactual about what would happen in a situation in which that law (or, rather, the law from which it is derived) is violated.  And I’m not convinced that any law can support a counterfactual like this.

This is a problem because Tooley is trying to draw a distinction between two classes of nomological truths (the laws proper and the logical consequences of laws).  He is arguing that the second class cannot support certain counterfactuals which the first class can – and that, therefore, they must be treated differently.  However, if he demonstrates this by pointing to a certain class of counterfactuals which are not only problematic for the second class, but for the first class as well, then he’s failed to draw the distinction.

So, I’ve been convinced by Dan that Tooley’s argument demonstrates that nomological truths like (L) all salt, when in water and near gold, dissolves in water. have difficulty supporting certain counterfactuals.  However, I haven’t been convinced that laws proper don’t face the very same difficulty.  On my understanding of things, if I can show that a plain jane law faces similar difficulties with the same kind of counterfactual, then I will have undermined Tooley’s distinction.

Tooley’s Laws of Nature and Counterfactual Support

In “The Nature of Laws”, Michael Tooley argues that some proper subclass of the nomological truths are laws of nature, since laws should support counterfactuals and not all nomological truths do that.

He says, “If one says that all nomological statements support counterfactuals, and that it is a nomological truth that all salt when both in water and near gold dissolves, one will be forced to accept [that if this piece of salt were in water and were not dissolving, it would not be in the vicinity of a piece of gold], whereas it is clear that there is good reason not to accept [that].”  (Last line in first paragraph of section 3.)

philosopher makes mistake

In “How to Define Theoretical Terms” (1970), David Lewis says the following. Take a theory T that introduced a new term ‘t’. Replace ‘t’ in T with an appropriate variable to form an open sentence R`. Lewis now claims that ‘t’ is correctly defined as follow:

t = the unique x such that R`

Note the uniqueness requirement. If there are multiple realizations of R` (that is, variable assignments that satisfy R`) differing in what they assign to x, then ‘t’ is denotationless. Van Fraassen (1997) argues that, provided only that T is consistent and has an infinite model, such will always be the case.

The Road to Ramseyan Humility

I’ve mentioned to a few of you around here that I think it is Lewis’ solution to “Putnam’s Paradox” that lands him in “Ramseyan Humility”. Here’s a sketch of why. I apologize for assuming some background familiarity with both “Putnam’s Paradox” and “Ramseyan Humility”, but I’m trying to keep things punchy.

Consider Lewis’ argument for Humility. Lewis’ assumes that T is realized by fundamental properties, which (because fundamental properties are plausibly wholly distinct from the roles they realize) allows Lewis to run the permutation argument to establish multiple possible realizations of T. But why does Lewis assume that T is realized by fundamental properties? There are actually several questions here. First, why does Lewis think that T is even prima face the sort of thing that is realized—that is, why does Lewis think that the Ramsey sentence approach to the content of T is the right one? Second, why does Lewis think that T is realized (rather than holding a non-representational interpretation of the Ramsey sentence as Sklar does)? Third, assuming that T is realized by something, why does Lewis think that T is realized by (metaphysically robust) natural properties [rather than, say, (metaphysically thin) classes]? And, finally, fourth, assuming that T is realized by natural properties, why does Lewis think that T is realized by completely natural properties, i.e., fundamental properties (rather than, say, natural “enough” properties).

Although there are four questions here, I think Lewis’ answer to the first three will be roughly the same: realism. His answer to the fourth question, however, can be found in RH where he makes a particular observation about scientific progress. Let’s take these questions in order.