Monday, November 14, 2011

Do We Need Essences?

I’ve just been starting to read and think more about essences, in particular the debate which has followed Kit Fine’s argument in “Essence and Modality” (1993) that essences cannot be understood in modal terms.  The modal understanding is that an essential property of an object is one is must have of necessity (in order to be that object), while properties it can (possibly) do without are accidental.  Fine, on his way to advocating a definitional notion of essence, said the modal understanding was too broad:  an object may have certain necessary attributes which are intuitively not essential.  In the paper, he offered some examples intended to bolster this point.

Now I’ve read a few papers which take issue with Fine’s argument. In particular, one line of protest, due to Michael Della Rocca, notes that Fine’s examples are of necessities which seem trivially true of all objects or existents, and the modal understanding of essence can be recast by a focus on non-trivial necessary properties.

For present purposes, though, I want to concede that there is an intuitive sense that essence seems prior to its modal understanding (even if the latter turns out to be extensionally equivalent):  when I try to think of what properties are necessary to an object I seem to be appealing to some non-modal definition I have in mind.

But do we really want to add essences as irreducible elements in our ontology? While I’m attracted to some Aristotelian or neo-Aristotelian notions (such as causal powers), my inner Occam wants to resist essences.

One clue to a way to think about this dilemma occurred to me while reading Michael Gorman’s paper, “The Essential and the Accidental”.  Gorman highlights one of the passages about the nature of essential properties discussed by Fine in another paper (“Senses of Essence”, which I have not read):  “An essential property of an object is a constitutive part of the essence of that object if it is not had in virtue of being a consequence of some more basic essential properties of the object; and otherwise it is a consequential part of the essence.”  Perhaps this constitutive subset should be the real target of our idea of essence.

While Fine’s idea of distinguishing consequential properties from constitutive properties is one of logical consequence, Gorman takes this as an inspiration to develop an account of essence that depends on the notion of explanation. Perhaps the essential properties of an object are those which cannot be explained by appeal to other characteristics (while accidental properties are those that can be so explained).  The paper elucidates this argument and considers possible objections.  This view is distinct from the modal understanding because it can accomodate necessary but non-essential properties.

For myself, being in a very preliminary stage of studying these issues, I reserve my opinion about Gorman’s particular strategy, but am led to a desire to link essences to some other metaphysical problem, such as causation (which is obviously related to explanation).  By the time we conceive of an object, we already have in mind something which has been caused and has its own causal powers.  And we already know (I believe) that modality alone, say a mosaic of categorical properties distributed across possible worlds as in David Lewis, doesn’t provide a theory of causation.  So, it shouldn’t be a surprise if there is a problem with defining essence solely in modal terms if essence relates to causation.   I’ll try to see what’s been written along these lines.

UPDATE: 20 November 2011:
Kathrin Koslicki has posted a preprint of a chapter for a forthcoming book called "Essence, necessity, and explanation" which fleshes out a discussion similar to Gorman's.  She uses an analysis of Aristotelian notions of explanation, including cause, to account for how necessary but not essential properties follow from constitutive essential ones.  However, the scheme here is that essence is basic and prior to cause (I was wondering if there was a way to reverse this priority.)