Confusing the Truth of Modality
Reinterpreting the Truth of Modal Statements through an Examination of David Lewis’s Modal Realism
ESSAY BY ROCKY SCHAEFER
I. Introduction - Abstract
David Lewis considers himself a modal realist, positing the existence of possible worlds which are of a kind like our own actual world, yet containing alternate circumstances. In this paper, I will start by outlining a few motivations, namely modality in ordinary language, which Lewis provides for reasons to metaphysically commit to possible worlds. Next, I will deconstruct Lewis’s reason for accepting the truth value of modal statements. I then identify an alternate interpretation of why we attribute truth values to modal statements on the grounds of a lack of epistemological access to modal truth makers. In developing this alternative interpretation, I will reject one of Lewis’s criterion for giving truth to modal statements, arguing that in giving truth to these statements one will run into logical trouble.
II. Motivations for Modal Realism
One of the major motivations for David Lewis’s belief in the existence of possible worlds is that modal language is uncontroversially true (Lewis, 182). For example, ordinary language permits statements of the sort: “it is possible that things could have turned out differently” (Lewis, 182). Intuitively, we grant truth value to these statements, because it seems likely that things could have turned out differently. Lewis claims that modal statements which plague our ordinary language are quantifiers over possible worlds, giving him the motivation to posit their existences (Lewis, 183). Another motivation for the existence of possible worlds is through the truth maker principle. The truth maker principle suggests that truths must have something to make them true. Thus, if we give truth to modal statements, there must be something that makes those statements true. Lewis provides possible worlds as truth makers for those true statements containing modal language.
Although Lewis affirms these motivations, he allows for some skepticism around taking ordinary language at face value. He states that taking ordinary statements at their face value is okay, unless (1) taking them at face is known to lead to trouble, and (2) taking them some other way is known not to (Lewis, 182). In this paper, I hope to identify how taking the truth of modal statements at their face value leads to trouble – fulfilling (1) – and suggest that fulfilling (1) is enough to consider a different theory.
III. Truth-Values of Modal Statements.
The truth of modal statements is different from the truth of non-modal statements. When I say “Paris is in France,” this is a statement that is true and has some epistemological evidence to it. I can validate this claim by going to France and witnessing Paris within it. However, when I say “Paris could have been in Germany,” I hesitate to give immediate truth to this statement. I think that the hesitation lies in a lack of epistemological access to the truth maker of this statement. Before, in the previous statement, I could find, and identify what made that statement true. However, with the latter statement this task is impossible. I don’t have access to the truth maker of modal statements – I merely assume that there is one, based off attributing truth to that statement. If we take Lewis’s interpretation to be true, he claims that we have no access to these possible worlds that make modal statement true (Lewis, 184). There are no directional, nor distance, nor causal relations between worlds. Thus in Lewis’s view we don’t have epistemological access to the truth makers of our modal statements. Perhaps this is fine. We may not need to be able to epistemologically recognize the truth makers of true statements. Perhaps it’s sufficient enough to just know that the truth maker exists.
However, I claim, relative to modal statements, that we are confusing “truth” with an inability to deny or falsify. Since we don’t have access to possible worlds the hesitation with giving truth value to modal statements comes from an internal logical debate in which we realize we cannot deny the modal statement. We cannot deny it, because we lack the access to it. I have no way to falsify possible claims, because they are beyond my epistemological reach. If someone proposes that “Paris could have been in Germany” I’ll respond with: “Sure, I guess it’s possible that Paris could have been in Germany,” but what I really mean is: “I don’t know if Paris could have been in Germany.” I can’t provide proof against modal statements and that lack of evidence is what I confuse with truth. This is different from giving truth to statements. Just because I can’t deny a statement doesn’t necessarily mean it’s true.
For example, let’s allow for Lewis’s possible worlds at the moment. Take the statement: “In no possible worlds is Paris in Germany”. This is saying that every possible world that exists doesn’t have Paris in Germany. Since we don’t have the epistemological reach to understand the natures of possible worlds, there is no way for me to deny this claim. Yet, simultaneously I may state: “Paris could have been in Germany”.
I can’t deny this claim for the same reasons. Thus we are left with two undeniable statements that express a logical contradiction in relation to one another. I believe this is trouble enough to fulfilling Lewis’s (1). In light of the alternative interpretation of the truth value of modal statements, I claim that there is no need to take these statements as true at face value, ultimately bypassing the need for fulfilling (2). Thus in fulfilling (1) and bypassing (2), Lewis’s claim that modal statements are uncontroversially true is rejected. Therefore, Lewis is left motivation-less for positing possible worlds, ultimately disrupting his theory.
IV. Possible Responses
In response, one might argue that the statement, “in no possible worlds is Paris in Germany” is false based of the truth of the statement “Paris could have been in Germany”. However, it is important to note that the truth of the latter statement is also up for debate. One may not falsify the validity of the former statement based of the truth of the latter, because the latter has yet to be shown to be true.
Lewis might respond, saying that there are some modal statements that can be proved false. This response may be motivated by his belief that impossible worlds don’t exist, thus statements containing illogical modal reasoning may be proved false (Lewis, 187). One might highlight such a claim by examining the relation between two modal statements. Saying that “Paris could have been in Germany” is somehow more plausible than saying, “it is possible that 2+2=5”. I will concede this response. In reply, I must make a distinction between logical and illogical modal statements, claiming that logical modal statements cannot be denied, while illogical modal statements may be denied on the basis of reasoning. This revision still allows my argument to stand and may have given it greater explanatory power.
V. Conclusion
In this paper, I outlined a few of the motivations that Lewis uses in order to posit the existence of possible worlds. Then I established a distinction between the truth of modal and non-modal statements by attributing the truth of modal statements to an inability to falsify due to a lack of epistemological access. Next, I provided a reason for why Lewis’s assumption of taking ordinary language at face value leads to trouble. I then concluded that reinterpretation of the truth value of modal statements disrupts a few of the motivations for accepting modal realism, suggesting that a different theory may be more agreeable. Finally, I considered a few possible replies that attempted to reject the claim that modal statements cannot be denied.
WORK CITED
Lewis, David. 1973. Possible Worlds. In The Possible and the Actual: Readings in the Metaphysics of Modality, ed. M.J. Loux. Cornell University Press.
Rocky Schaefer is a senior at the University of Washington, majoring in Philosophy and minoring in Math, Art, History, and Latin. You can reach him at rockysch@uw.edu.