If a and b are identical, they will share all the same properties. If a has properties x, y, z, so too will b. But there is a strange property that many ontologists refer to and sometimes believe in: the property self-identity. An object or thing is identical with itself. So let’s get back to the identity (or not) of a and b. One of b’s essential properties is being self-identical (i.e., being identical with itself). If a and b are necessarily identical, therefore, a must have this property being identical with itself. Therefore a also needs to be identical with b because b has the property being identical with itself. It follows from this that a is necessarily identical with b. Yablo argues that a and b can’t be contingently identical.
In the literature, ontologists say that identicals are indiscernible, and Yablo says that “discernibles are distinct”. To clarify this, Yablo argues that
if a has a property necessarily which b has only accidentally, then a is distinct from b.
We must bear in mind here relational and positional properties because two objects can be identical except for relational and/or positional properties. For example, two objects can be identical except for the property that is their position. One may be in America at t and another in France at t1. Another example could be that two people are identical but have different, say, relatives (these are unrealistic possibilities!).
Throughout the paper Yablo talks about a bust and a hunk of wax. A bust made out of that hunk of wax. Intuitively Yablo says something that is very strange. He says that the
bust and the hunk of wax are not the same thing
even though the bust is made up exclusively of the hunk of wax. This is how he argues his case. He writes that
the bust of Aristotle is necessarily a bust of Aristotle.
That is, the bust can only be a bust and nothing else. It can’t, for instance, be a chip pan or a dog. The hunk of wax, on the other hand, is a different matter. Yablo says that it is “only accidentally a bust of Aristotle”. This means that the hunk of wax, qua hunk of wax, could have been something else other than a bust. It could, for instance, have been shaped into a bust of Stephen Yablo. Alternatively it could be a shapeless hunk used as a doorstopper. So it is not necessarily a bust, but it is necessarily a hunk of wax. The bust, on the other hand, is necessarily a bust. It too could be used as a doorstopper, but it would still be a door-stoppingbust. That is, a bust used for stopping doors rather than for looking at. .
Yablo concludes from all this that the
bust and the hunk of wax are not the same thing.
Or at least at this stage he allows for the possibility that they are not the same thing. It is hard to follow, at this stage, why he thinks that the hunk and the bust are not identical, even if one accepts the points about necessary identity. Nevertheless, he does acknowledge that
it would be incredible to call the bust and the wax…distinct.
That, of course, is his intuitive or prima facie view.
Yablo provides some interesting comparisons between the bust and the wax and other pairs. For example:
1)“a neural event subserves the corresponding pain…”
2)“a computer’s structural state instantiates it computational state…”
3)“a society is nothing over and above its members…”
4)“the driving hone generates the speeding home…”
My first reaction to these four examples is that they are not all of a kind. The last two examples seem to form a similar kind. And so too do the first two. Firstly, and intuitively, there seems to be a big difference between a neural event or a brain state and a pain. So too between the concrete structure of a computer and its computations. However, the “driving home” seems to be numerically the same thing as the “speeding home”. They are simply two descriptions of the same thing, not unlike the way ‘the Morning Star’ and ‘the Evening Star’ are different names for the same planet (i.e., Venus). The third example I find the most problematic. The majority of people, I think, seem to believe that a society is something “over and above its members”. Do they advert to emergent properties by doing so? Possibly they do. You could also cite emergence arguments for example 1), 2) and 3). The odd one out, in that case, would be number 4). There is no real hint of genuine emergence in that example. But what of the hunk of wax and the bust? This is how Yablo explicates their relation to one another:
5)“the hunk of wax composes the bust…”
Here also there is no hint of basic emergence. In fact the word “composes” is not very helpful here. What precisely does that word mean in this context? This explication of the relation between the wax and the bust is harder to make sense of, I think, than the other four examples.
Essentialism
Yablo then goes into essentialist territory and makes a distinction between essential and contingent/accidental properties. This is how he defines them both:
essential properties: ‘those [properties] which a had to have…”
contingent properties: “those [properties] which [a] merely happens to have.”
If a didn’t have its essential properties, it would not be a. That is, a could not be a or even exist asa without its essential properties. Its essential properties make it what it is (whatever that is). a’s contingent properties it could do without. If it lost them, it would still be a and it would still exist asa. It “merely happens to have” these properties – they aren’t necessary.
Yablo goes into detail about the relevance of essential and accidental properties. He says that
the properties a merely happens to have reveal nothing of what a is.
For example, someone may argue that Socrates’ snub nose reveals “nothing of what [Socrates] is”. His wisdom, on the other hand, must reveal something of what he is or was. Yablo quotes Antoine Arnauld here. He makes more or less makes the same point:
“…it seems to me that I must consider as contained in the individual concept of myself only that which is such that I should no longer be me if it were not in me…”
Yablo says that we can lose all non-essential properties when we characterise an object or a person. He calls the set of essential properties the “complete essence”. Of course different things will have different amounts of essential properties.
Again, what is the essence of a thing? According to Yablo it is
a measure of what is required for [a thing] to be that thing.
This means that different things not only have different essences but different amounts, as it were, of essence. Therefore a may require a “stricter” or larger essence than b. Yablo gives an example of this: the Shroud of Turin and a piece of cloth (which he calls the “Cloth of Turin”). Ostensibly, because the Shroud is made up of cloth, the cloth and the shroud may seem to be identical or indistinct. However, Yablo believes that the Shroud has a “bigger essence” than the cloth taken qua cloth. Obviously the Shroud has the property being a cloth but also being a Shroud. The cloth taken qua cloth clearly hasn’t got this property. But doesn’t it have a negative quality – the quality not necessarily being the Shroud?
What does it mean to say that a has property P essentially or necessarily? According to Yablo there are two possible answers to the question:
When will a have P necessarily?
The two answers are:
1)“when [a] has P in every world…”
2)“when [a] has [P] in every world in which it exists…”
Yablo rejects 1) because then “everything necessarily exists”. Perhaps this means that every object exists in every possible world because everything has the property existence. But isn’t to have “P in every world” just to say that P is necessary or essential to an object (or to a)? I don’t quite follow Yablo’s reasoning here. When we say that
a has P necessarily.
we don’t mean that a has P in every possible world; it only has P in the worlds in which it exists. If a existed in every possible world, and had P in every world, then it would be a necessary being.
Yablo reiterates:
…an attribute is necessary to a thing if it attaches to the thing in every possible world…
Yablo argues at one point that the Shroud of Turin is distinct from the cloth of Turin. His reason for this belief? He believes this because
the Shroud of Turin…had to enshroud Jesus.
This almost seems like a truism or a tautology. Of course the Shroud of Turn had to enshroud Jesus otherwise it wouldn’t be called the “Shroud of Turin”. We could call these two names, “the cloth of Turin” and the “Shroud of Turin”, “rigid designators” in the manner of Kripke. That is, they rigidly designate the same thing in all possible worlds. (Incidentally, Yablo capitalises “cloth” is the “Cloth of Turin”, which appears to suggest that he is using it as a proper name.) Therefore Yablo’s statement has the air of analyticity about it. Perhaps if the name “Jesus” were substituted with the description
the man who was enshrouded by the Shroud of Turn.
it would then be more obviously analytic. Perhaps not. Anyway, according to Yablo the cloth of Turin did not necessarily enshroud Jesus. The cloth of Turin could have been used exclusively as, say, a dishcloth!
So the cloth and the Shroud are seen, by Yablo, as contingently identical. It is only an accident or coincidental fact that the cloth of Turin enshrouded Jesus and thus became the Shroud of Turin.
Yablo says that
[I]n every ordinary respect the two are exactly alike.
So what respect, exactly, is not ordinary? Its essential properties? But what are the Shroud’s essential properties (other than the fake, vacuous or “trivial” ones like self-identity)?
Dana Scott, referred to by Yablo, seems to refer to this extraordinary respect. Yablo quotes Scott thus:
“two individuals that are generally distinct might share all the same properties (of a certain kind!)…”
Perhaps this non-shareable respect is the substrate or bare individuator referred to by certain ontologists. Perhaps it is an essence of some other description (if bare individuators aren’t themselves essences).
Anyway, Yablo elaborates on what may be Scott’s position. Here again he makes a distinction between essential and contingent properties. He talks about contingent, rather than essential, identity. That is
…a and b are contingently identical…if and only if they have the same contingent properties…
These contingent properties will include size, weight, colour, etc. One might ask here: What’s left after all these contingent properties have been taken away? What indeed! There must therefore be something other than size, weight, colour, etc. that distinguishes the bust from the hunk of wax. Again: What is it?
To put the above in Yablo’s technical language. There is a possible world in which the bust lacks any or all of these contingent properties. Can it loose all of them and still be the bust (or a bust)? Of course not!
Yablo again stresses what it is to have an essential or necessary nature. You see it’s not just a case of “how a thing actually is”, it’s also a case of
how it would or could have been if circumstances had been different.
So when we describe the essential or necessary nature of a, we are not just referring to what a is now, we are also referring to what amust be, would be, and could be if it existed in the future rather than at the present time. So let’s pretend that a doesn’t exist now but will exist in the future. When a exists it will have the same necessary or essential nature that it has now. If it did not have this essential nature, it would not be a at all.
What would it take for a [say, the Shroud] and b [say, the cloth] to be identical? According to Yablo:
if [the wax] and [the bust] are strictly identical, [the wax] will exist in exactly the same possible worlds as [the bust], and [the wax] will be coincident with [the bust] in all of them.
Yablo is saying that the bust could exist in W1 and not be made of wax, whereas the wax will always be self-identical in all possible worlds. That is, the bust could be made of chocolate because being made of wax is not an essential property of the bust or of a bust. So what is? Alternatively, the wax could exist in W2 and not actually be a bust: it could just be a shapeless hunk or a square doorstopper.
So the bust and the wax are only contingently identical, not necessarily identical. As another example of this, Kripke famously argued that brain state X may be contingently identical to mental state Y, but they are not necessarily identical. Therefore mental state Y could be subserved by something other than brain state X or subserved by nothing at all, as in Cartesian dualism. Kripke concludes that brain state X and mental state Y are therefore not identical, not even contingently identical.
Sortal Identity
In the last section Yablo comments on the importance of types or kinds when it comes to individuating individuals. Two individuals are not simply the same, they are the same something (type or kind). Wiggins did important work in this area, and Yablo quotes the philosopher thus:
“…the g-identity, for some one sortal concept g, of x and y.”
The ‘g’ is a sortal concept that could be, in this instance, a bust or a shroud.
Yablo provides a powerful argument, based on the work of Kripke, for what brain state X can’t be identical to mental state Y (say, a pain). He divides the situation three ways:
1)Smith’s toothache
2)Neural event v
3)Neural event e
Are 1) and 2) identical? We can happily accept that 2) causes 3), but if 1) is identical with 2), then 1) must also cause 3). But, Yablo asks, can Smith’s toothache cause a neural event? Yablo says that
v’s being Smith’s [toothache] contributed nothing to its production of e.
But why can’t a toothache cause a neural state? Is this a denial of mind to brain causation (i.e., a epiphenomenalist argument)?
Yablo offers an alternative argument. 1) and 2) are only coincident:
they will have different causal powers and susceptibilities.
(in the manner of Davidson). So what kind of causal powers would Smith’s toothache have, exactly?
Reference
‘Identity, Essence, and Indiscernibility’, Journal of Philosophy 84 (1987), ColumbiaUniversity
