A Brief Objection to the Conjunction of Schaffer's Contrastivisms

To begin, I want to consider a sentence that I think I understand.

S. Jones knows that Suzy’s throwing the rock caused the window to break.

By claiming to understand this sentence, I do not mean to suggest I have complete and fully worked out views providing informative analyses of knowledge or causation. I simply claim that the sentence makes sense to me. A helpful comparison is to a sentence like this:

S’. Jones knows that Suzy’s throwing rather than tossing the rock caused the window to break rather than shatter, rather than that Billy’s throwing rather than tossing the rock caused the window to break rather than shatter.

While I don't claim that I am outright unable to parse such a sentence, S seems comprehensible to me in a way that S' does not. And this is the basis of one concern I have surrounding the conjunction of Jonathan Schaffer's contrastivisms.


Schaffer is a contrastivist about knowledge. Specifically, rather than taking knowledge to be a binary relation obtaining between an agent and a proposition, Schaffer takes it to be a ternery relation obtaining among an agent, a proposition, and a contrast proposition. As part of the linguistic story required to make this view of the knowledge relation jive with apparently binary knowledge ascriptions (e.g. "Jones knows that grass is green"), Schaffer maintains that such apparently binary sentences are contextually supplemented with a contrast proposition. Essentially, the assertive utterance of "Jones knows that grass is green" in a given context expresses a proposition equivalent to the content of some sentence like "Jones knows that grass is green rather than blue." The question at issue in the context of assertion determines which contrast proposition is contributed, but the explicitly contrastive claims are not themselves context sensitive.

Schaffer is also a contrastivist about causation. Specificially, rather than taking causation to be a binary relation obtaining between pairs of events, he takes it to be a quaternary relation obtaining among one event, a class of events contrasting that first event, a second event, and a class of events contrasting that second event. As part of the linguistic story required to make this view of causation jive with apparently binary causal claims ("Suzy's throwing the ball caused the window to shatter"), Schaffer maintains that such sentences are contextually supplemented with the contrast events. Essentially, the assertive utterance of "Suzy's throwing the ball caused the window to shatter" in a given context expresses a proposition equivalent to the content of some sentence like "Suzy's throwing rather than tossing the ball caused the window to shatter rather than crack". Again, the contextualist element of the view only has to do with superficially binary causal claims, while explicitly contrastive claims are not themselves context sensitive.

Now, on the conjunction of Schaffer's views, assertive utterances of S ("Jones knows that Suzy’s throwing the rock caused the window to break.") express a proposition along the lines of that expressed by S' ("Jones knows that Suzy’s throwing rather than tossing the rock caused the window to break rather than shatter, rather than that Billy’s throwing rather than tossing the rock caused the window to break rather than shatter."). But since I generally understand assertive utterances like S and have a lot of difficulty parsing assertive utterances of S', it seems as though this is a rather significant problem for Schaffer's view. The complexity of embedding a causal claim (or, for that matter, a knowledge ascription) within a knowledge ascription, is much higher, on Schaffer's view than on a binarist approach to causation and knowledge.

I am sure that there are things for a proponent of the views to offer, but it does strike me as something that requires an answer.