My continued existence depends on lots of things. It depends on my breathing oxygen. It depends on food, water, and my not getting run over by a bus. We might say that these things are essential for my existence, since I would not exist without them. Moreover, my relation to other people may be essential to my existence. If it weren't for my uncle Mike and his power and influence in the "family", my enemies would have iced me by now. These enemies still wait in the wings. If anything were to happen to Uncle Mike, I'd be a gonner. One other example is from Paul McCartney, who wrote, "I won't live in a world without love". There are many contingent features of the world without which one would not exist.
In philosophical circles, by contrast, we require that any essential property of a thing be a necessary property of the thing. We say that something is an essential property of x iff x has the property in every possible world in which x exists. But 'essence' is said in less strict ways in the vernacular. If the doctors need to operate immediately in order to save your life, then time literally is of the essence. This suggests that the philosophical account of essence is too strong to capture ordinary use. I noted in the previous post that Berit and I agree with Fine that the strict philosophical account is too weak, for the reason that on that account any necessity is an essential property of everything. I believe that the alternative account, proposed in the last post, handles both problems nicely. The account was this:
(1) x is essentially F iff if nothing were F then x wouldn't exist,
or semantically,
(2) all the closest worlds (whether possible or impossible) where nothing is F are worlds where x doesn't exist.
Thanks to Mike Almeida, who pointed to an objection to this account (in the comments thread of the previous post). His worry boils down to this: it follows from (2) that some essential properties are contingent properties. However, as Mike has inspired me to argue here, I think this is a virtue of the account, and not an objection. The account expressed by (2) handles both the strict philosophical, and a predominant ordinary, use of 'essence'.
The key is to note that the closeness relation widens or narrows with the conversational context; the closest worlds are ones that preserve the highest proportion of the relevant background facts at the actual world. In the typical strict philosophical context where essential properties (for whatever reason) are expected to be necessary properties, the relevant background facts are the facts about what is metaphysically possible. So, the closest worlds will be all the metaphysically possible worlds. (The exceptions are philosophical contexts in which impossibilities are sincerely entertained. See previous post.) In the ordinary, non-philosophical, contexts alluded to at the beginning of this post, the relevant background facts include, for instance, that McCartney was suicidal after the loss of a girlfriend. Hence, the closest worlds without love are worlds where McCartney kills himself. Therefore, if there were no love, McCarney would cease to exist. By (2), it follows that being loved is essential to McCartney's existence. Or consider that the background facts include that I just don't run from, or rat out, other mobsters (because I'm just that brand of Sicilian American wise guy). Then the closest worlds without protection from Uncle Mike are worlds where I'm dead meat. Yes, I could go into hiding or witness protection, but then I would no longer be the wise guy that I am. So, by the above account, it is essential to what I am that I am protected by Uncle Mike.
In sum, the traditional account of essence (in terms of what properties a thing has in every metaphysically possible world in which it exists) is both too strong and too weak. Account (2) seems to take care of these problems.
