My Top Philosophy Pieces of 2019, #4
In the previous post, I mentioned that Menzel’s paper asks an important question about essential properties that clarifies central discussions and debates surrounding modal properties. Those issues are the subject of another paper on modal metaphysics that has been a staple in my thinking, Edward Zalta’s “Essence and Modality”.
5. Christopher Menzel, “In Defense of the Possibilism-Actualism Distinction”.
4. Edward Zalta, “Essence and Modality”.
Like most people who are interested in what essence might be (granted, it’s not a large group of people, relatively speaking) and who start to read up on essential properties, typically you’ll see ‘essential property’ defined as something like this: a property is an essential property iff necessarily, if some thing exists then it has that property. Necessarily, if I exist then I have the property of being human; arguably, if I exist then I can’t be an earthworm. So the property of being human is one of my essential properties; without it, I wouldn’t be what I am. Though the idea of essence can be elusive (apart from kitchy men’s fragrances), the above definition seemed pretty stable.
Until recently. Kit Fine came up with a bummer of a counterexample to that definition: if there is the set of Socrates that has only Socrates as its member (this kind of set is called a ‘singleton’), then necessarily if Socrates exists he has the property of being a member of that singleton set. So Socrates essentially has the property of being a member of that singleton set, just as the singleton set essentially has the property of having Socrates as a member. But if we think that essential properties are supposed to be tied to the nature of things in some way, then although it does seem part of the singleton’s nature to include the property of having Socrates as its member, it does not seem part of Socrates’s nature to have the property of being a member of his singleton set. In other words, it doesn’t seem like that property makes Socrates what he is, in a way that the property of being human is part of his nature.
So Fine comes up with a complicated logic to try and solve this dilemma, but Zalta uses his own object theory to come up with a solution that does not involve adding as many formal features as Fine’s theory. There are, however, a couple things to know about Zalta before picking up one of his articles. First, he is as capable a metaphysician as just about anyone you can think of — he is a Senior Research Scholar at the Center for the Study of Language and Information (CSLI) at Stanford and heads up the Metaphysics Research Lab there. Second, if you don’t have pretty advanced training in logic, most of his papers won’t be accessible in all their detail. Third, he is a necessitist, and his object theory reflects this in affirming that, necessarily, everything necessarily exists. I mention that because his solution to this problem depends on that aspect of his theory.
This piece made such an impression on me because of its formal rigor and clarity, as well as the solution he gives that seems to match some of our intuitions about what essential properties are and how they should behave. After arguing a few points in great detail, his solution to the problem involves distinguishing between necessary properties, which necessarily an object has, weakly essential properties, where necessarily if an object exists (or rather, is concrete, as I’ll explain) then it has such a property (this is sort of like the old-fashioned definition of ‘essential property’ mentioned above, but interpreted differently within his theory), and strongly essential properties, which are properties that are weakly essential but not necessary.
Why is this important? On this theory, I (along with everything else) exist necessarily (though I’m not necessarily concrete), but I have the property of being human contingently, because there are other possible worlds where I exist, but I am only human in the actual world; in those other worlds I’m just a possible object rather than a flesh-and-bones human. So being human is not a property I have necessarily. But thanks to Zalta’s solution, it is a property I have both weakly essentially and strongly essentially. Now, take the property of being a member of my singleton set. This is that property that, on the old-school definition, would be an essential property, contrary to our intuitions about essence and nature. Being a member of my singleton set is a property I have necessarily; I have it in every world. And I have it in every world in which I am concrete, so the property is a weakly essential property. But it is not a strongly essential property like being human, because I have the property of being a member of my singleton necessarily. So this distinction captures how we want to think about essential properties and how they relate to an object’s nature.
Anyone who is interested in the topic of essence, existence, and nature cannot afford to overlook this article. It’s certainly not the only thing to read on those topics, but the way Zalta presents the problem and the way he then offers a solution makes the piece essential reading (pun intended) for those thinking about these and related issues.
3. Aaron Cotnoir, “On the Role of Logic in Analytic Theology: Exploring the Wider Context of Beall’s Philosophy of Logic”.
2. Language Turned on Itself: The Semantics and Pragmatics of Metalinguistic Discourse, Herman Cappelen and Ernie Lepore.
- Paul Taylor, Black is Beautiful: A Philosophy of Black Aesthetics.
