Tuesday, December 25, 2007

Essences can be contingent

Merry Christmas everyone!

I have nothing profound to say for Christmas, so here is a bit of philosophy. The Logos became a human being. He existed eternally, but only from around 4 BC was he a human being. Here is an interesting philosophical conclusion one can draw from this: Being human is not always a modally essential property of a human being, where a modal essential property of x is one that x cannot lack. For the Logos has the property of being human, but it was possible for him not to have this property.

This raises an interesting question. Is humanity a modally essential property of us? If yes, then the same property can be modally essential in one being but not in another. This isn't very surprising. (If we allow disjunctive properties, it's easy to come up with such properties. Thus, an electron modally essentially has the property of being a non-elephant or weighing 7000 pounds. It is possible for an elephant to have this disjunctive property, but it will not have it essentially--if it gains or loses weight, it'll lose the property.)

Suppose not. That would have the following interesting consequence: We could hold on to Aquinas' idea that when the body is dead and only the soul is alive after death and before the resurrection, the human being does not exist, while at the same time accepting that we will exist at that time, reduced to a soul.

But I suspect that we are modally essentially human, unlike the Logos. So I have to give a different story about the resurrection. I actually think it's possible to be a human being without a body, though this is a severely defective state.


Mike Almeida said...

Merry Christmas, Alex!

You say,

Being human is not always a modally essential property of a human being

Plantinga at least suggests that Socrates could have been an alligator, if the latter is just an mind-alligator-body composite (NN, 65ff). That seems to entail that, as far as AP is concerned, there is some sense in which Socrates, and you and I, are contingently human.

Alexander R Pruss said...

Merry Christmas, Mike!

If substance dualism were true, then we probably could have an alligator body. We perhaps could even have two alligator bodies at once, as long as some way to integrate the sensory inputs were found.

Bill said...

I can be an unembodied human being, Alex? If I can do that, then like the phrase "human organism," the phrase "human being" is vague. I read an article an article about abortion, where the author distinguished between being a human person and being a human organism. Being a human person implies being a human organism. But being a human organism does not imply being a human person. You might say that a human ovum is a human organism because a human ovum is living thing that only women produce. But you wouldn't say that a human ovum is a human person. I seem to remember that the article's author was distinguishing between human organisms and human persons to argue that abortion is sometimes morally acceptable if yet-to be-born human organisms are not human persons.

Saint Thomas Aquinas tells us that each human person consists of both a human body and a human soul. If he is right, then a human soul is a proper part of the person to whom that soul belongs. A proper part of an object is a part that is not identical with the whole of which it is a part.

Imagine that there is a difference between being s human organism and being a human person. Then the phrase "human life" is vague when someone says that human life begins at conception. Since I'm a Catholic, and since the Catholic Church teaches that abortion is always murder, I say that a new human organism's human personhood begins when that organism's parents conceive him.

Alexander R Pruss said...


I don't think the fact that I can be an unembodied human being implies that "human being" is vague.

An ovum is not an organism, I think. It is just a part of an organism.

I am actually willing to bite the bullet and say that a human organism can survive reduced just to a soul. I think this only works if "soul" is understood hylemorphically.

I would modify St Thomas' view here. Normally, the human being or human organism is composed of body and soul. But under abnormal circumstances, viz., after death, the human organism is composed just of soul.

Now one might try to run the following reductio against this view. Let s be x's soul:
1. At t0, x has s as its proper part. (Premise)
2. At t1, x is identical to s. (Premise)
3. Identity is not contingent. (Premise)
4. Therefore, x is always identical to s. (By 2 and 3)
5. Therefore, at t0, x has x as its proper part. (By 1 and 4) But that is absurd.

This form of argument, however, is just a version of the argument that sets up the Problem of Material Composition. For the classic example, suppose Tibbles the cat loses his tail at t1. Let s be the part of him that consists of everything but the tail. Let t0 be the time at which he has the tail. Then the argument seems to work, and produces an absurdity.

But it is clear that cats can survive loss of tail. So there is something fishy about arguments of this sort.

The literature has a number of solutions, a number of which work in the soul-body case as well. Let me mention two, one of which is not very popular, but I think may be right.

1. (The more popular.) Deny that (2) is an appropriate description of the situation where x has lost everything but s. It does not follow from this situation that x is identical with s (whether s is the soul or Tibbles minus tail). All that follows is that x is solely composed of s. But composition is not identity.

2. (The less popular.) Deny (1). There is no such thing as Tibbles-minus-tail as long as Tibbles has a tail. Likewise, the soul is not a distinct entity, strictly speaking, of which we could say that it is a "part" of the whole. On hylomorphic views this is not implausible. On Thomas' view, the soul receives its individuation from the matter. Spelling this out would be tough, and I have little more beside these cryptic remarks.