In the “nuts and bolts” series, I explain and discuss some of the fundamental ideas in philosophy (and theology sometimes) that are taken for granted within the discipline, but which might not be very well known to ordinary human beings. This time the subject is nominalism.

Do tables exist? Do all red apples (assuming that apples exist) have something called “redness” in common? These might strike most people as pretty weird questions, but questions like these are at the heart of the distinction between realism and nominalism. They’re both ways of addressing the problem of universals. We classify things all the time; as circular, as yellow, as an elephant, as a mountain, as a snail, as wooden, as evil, and so on. Nominalism and realism are alternative ways of thinking about what we’re actually doing when we classify things this way. I’m going to be zooming in on nominalism here, but I’ll be simplifying heavily in the spirit of only attempting to provide the nuts and bolts, without going into a whole lot of depth.
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Here’s the fourth installment on my series on the mind-body problem.

In this episode I look at the argument against physicalism from the afterlife. Here, some dualists argue that if physicalism were true, then the resurrection of the dead would be logically impossible. Their argument is:

1. The doctrine of the resurrection of the dead entails that people will be raised back to life who are the same people who died long ago. In other words, they will have the same identity.
2. Sameness of identity requires unbroken metaphysical continuity (that is, the continued, uninterrupted or “non-gappy” existence of whatever thing the functioning person is, whether a physical thing or an immaterial mind).
3. In physicalism, it is logically impossible for there to be unbroken metaphysical continuity between a physical person who died a hundred years ago and a person who will be raised to life in the future.
4. Therefore if physicalism is true, the doctrine of the resurrection of the dead is logically impossible. Stated differently, a physicalist cannot consistently believe in the resurrection of the dead.

How might a physicalist respond to this line of argument? Listen to find out. As promised in the episode, here are a few pieces of work by Trenton Merricks that relate to some of the material I cover:

“How to Live Forever Without Saving your Soul,” in Kevin Corcoran (ed.) Soul, Body, and Survival: Essays on the Metaphysics of Human Persons (Ithaca: Cornell University Press, 2001), 183-200

“There Are No Criteria of Identity Over Time,” Noûs 32:1 (1998), 106-124.

“The Resurrection of the Body and the Life Everlasting” in Michael J. Murray (ed.), Reason for the Hope Within (Grand Rapids: Eerdmans, 1999), 261-286.

Enjoy.

Oh, one other thing: I’ve added a new feature to the blog: Buy me a beer. So if you like this episode, feel free to shout me a pint!

Glenn Peoples

 Episode 032: In Search of the Soul, Part 4 [48:03m]: Play Now | Play in Popup | Download

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This is the second installment in the “nuts and bolts” series of blog posts, where I take some of the “nuts and bolts,” the basic concepts employed within philosophy (and later I suppose I’ll use examples in theology as well) and explain them for those who might not be as familiar with them as people who encounter them a lot.

Recently while I was giving a public talk on the contentious issue of abortion, I made reference to the idea of “numerical identity.” In context, I was explaining that even though the features of a fetus will change considerably over time during gestation, and will continue to change considerably after birth as well, although its qualities at one point are not identical to its qualities at a later point, it is still the same entity. In technical terms, I explained, it remains “numerically identical” the whole time, and so I, an adult, am numerically identical to a fetus that once lived.

This term caused a bit of confusion for a couple of people in attendance. For example, one man thought that “numerically identical” just meant “a set made up of the same number of things.” He objected, for example, that my comments summarised above committed me to the claim that I am identical to one of my hairs. After all, there’s just one of me, and if I pluck out a hair, there’s just one of it too, so the two things would be numerically identical (after all, 1 = 1)! So I’ve decided to make this second nuts and bolts blog post all about the concept of identity. It’s not the most riveting of subjects, but a pretty important one in philosophy one nonetheless.

So what is identity? Although it’s a term used in philosophy, it certainly isn’t unique to the field of philosophy. Philosophy isn’t an abstract, arcane discipline unto itself. It’s an approach to concepts and ideas that actually apply to the whole variety of disciplines, subjects and issues that all of us interact with in our lives as we use or employ language, science, medicine, as we engage new beliefs, come up with new ideas about the universe, decide how to evaluate theories, pursue justice and so on. Philosophers have had plenty to say as they have explained and discussed this concept of identity that all of use use in everyday speech and life, whether we realise it or not. For example, it gets used in police line ups (e.g. “looking at these five people, can you identify the man who robbed the bank?”), it gets used in romance novels (e.g. “could this really be the same man I knew all those years ago as a child?”), it gets used in our study of the natural world (e.g. “scientists tagged the salmon so that in the months to come as they tracked its movement, they could identify it as the one they were studying”), it gets used in spy movies (e.g. “my cover was blown. In spite of my changed appearance, the KGB now knew who I really was”), and so on.

Whether we’re aware of it or not, all of these scenarios are taking for granted the most fundamental of all logical laws, namely the law of identity (http://en.wikipedia.org/wiki/Law_of_identity). It is both simple and obviously correct, and is as follows:

A = A

That’s it. In English, it is best stated this way: “everything is identical with itself” (or ?A = A, “necessarily, everything is identical with itself”). This may seem fairly trivial and obvious, but it requires us to distinguish between two important concepts of identity. The law of identity is referring to what is called “numerical identity,” although there is another way that things can be identical, namely by being “qualitatively identical.”

In order for entities to be qualitatively identical, they must share all the same qualities (i.e. their qualities must be identical). Two perfectly manufactured ping pong balls would be qualitatively identical provided they are made exactly the same way. To see the difference between the two kinds of identity, consider this: Imagine that I showed you those two ping pong balls and asked you to point to one of them. Next, imagine that I were to put those ping pong balls behind my back and switch them between my hands a few times. Then imagine that I held them out to you, one in each hand, and asked you “which one is identical to the one you chose?”

You could react in one of two ways, depending on how you interpreted my question. If you thought I was talking about qualitative identity, you might say “they are BOTH identical with the one I pointed to earlier.” And you’d be right if that was what I meant. But that’s not what I meant. What I’m talking about now is numerical identity. Imagine that unbeknown to you, each of the ping pong balls had a name, X and Y. The one you had pointed at was Y. In terms of numerical identity, the correct answer to my question is “Y. Y is identical with the ball that I originally pointed to.”

Numerical identity has nothing to do with the qualities that a thing (or person) has. It has everything to do with whether something is the same object or entity as another. Here’s another example to hopefully make this distinction clear: Imagine that you were a witness to a murder on a cold and dark autumn night. You got a good clear look at the killer standing under a street light. He had a menacing scowl on his face, a long beard, and wild woolly red hair. Now you stand in the dock as a witness as this man stands trial. The prosecution lawyer asks you – “is that man the same person you saw at the scene of the murder?” You look over at the accused man. He has had his hair cut short since that terrible night, and now he’s clean shaven as well. From what you’ve heard, he has changed his attitude as well. He felt so terrible because of what he had done that he has really turned his life around, and now he wouldn’t hurt a flea. Because of all these changes, you say to yourself, he’s not the same man anymore. So you say to the lawyer, “No. That’s not the man I saw that night. He’s different from that man.”

Of course, you can see exactly what’s wrong with this answer. The person in the dock is confusing two different understandings of the word “same,” each of which deals with a different type of identity. This man’s qualities have changed over time, so in a qualitative sense he’s different, but it’s still true that he’s the same man as the murderer in a numerical sense. This could have been easily demonstrated if, on the night of the murder, you branded a number into his rump – the number 75 (Why 75? Well, why not!). That way, when standing in the dock, you could have simply asked the man to drop his trousers, and then you could declare – “Yes, that man has the identity of (i.e. he is identical with) the killer I saw that night. You would have established that whatever changes he might have undergone, he is numerically identical with the killer (unless of course there’s another man with the number 75 branded onto his rear, but we won’t go there).

Stated differently, numerical identity means that if everything in the universe had a different number assigned to it (and only one number), the things that I have in mind share that number (meaning that they aren’t different things, but rather the same thing after all). Take for example the fetus that was in my mother’s uterus six months before I was born. Give it a number (let’s pick 498,178, 895, 659). Then look at me, sitting here typing this. What’s my number? It’s 498,178, 895, 659 – the same number as that fetus. The fetus has kept that number for more than 33 years, and now that fetus sits here, typing. I am therefore numerically identical with a fetus that once existed (of course what exists now is not a fetus but an adult).

So there you have it, the concept of numerical identity.

Glenn Peoples

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I’m doing some writing on the concept of numerical identity at present, so I thought it might be interesting to consult Google to see what others have said about it. I can usually rely on the contributors to the Standford Encyclopedia of philosophy, but this time somebody (Harold Noonan), I daresay, got it wrong. He writes:

To say that things are identical is to say that they are the same. “Identity” and “sameness” mean the same; their meanings are identical. However, they have more than one meaning. A distinction is customarily drawn between qualitative and numerical identity or sameness. Things with qualitative identity share properties, so things can be more or less qualitatively identical. Poodles and Great Danes are qualitatively identical because they share the property of being a dog, and such properties as go along with that, but two poodles will (very likely) have greater qualitative identity. Numerical identity requires absolute, or total, qualitative identity, and can only hold between a thing and itself. Its name implies the controversial view that it is the only identity relation in accordance with which we can properly count (or number) things: x and y are to be properly counted as one just in case they are numerically identical (Geach 1973).

This is mostly correct. Yes, there is a fundamental distinction between numerical identity and qualitative identity. Two things can have all the same qualities (e.g. two rubber balls made on the same production line) and so be qualitatively identical, but because there are two balls sitting side by side and not one ball, they are not numerically identical. When you’re counting how many balls there are, you have to count two, or you’ve missed at least one.

But Noonan goes very wrong when he says that “Numerical identity requires absolute, or total, qualitative identity.” It actually requires no such thing. Consider for example the following scenario, especially the question: “Martha says this is my long lost husband. He looks so different. Could he really be the same man I knew ten years ago?” The question clearly makes sense, and it is clearly a question about identity. But it is not a question about qualitative identity. The questioner already knows that the man she now sees and the man she was married to ten years ago are not qualitatively identical. The man she sees before her looks different, so he has different qualities. The question is whether or not this man is numerically identical with the man she once knew. And this question is one that could quite conceivably be answered in the affirmative. This is because – as is perfectly obvious once we see what the distinction between numerical and qualitative identity is – there is nothing at all about numerical identity over time that requires qualitative identity.

It’s possible that Noonan would grant the error if it were pointed out to him, and qualify his statement somewhat to say something like: “At any fixed point in time, not allowing for qualitative change, a thing’s being numerically identical with something requires that it have qualitative identity with it as well.” But as it stands, it’s a bit of a howler.

The reason I was doing the search in the first place was because I’m preparing a piece on the abortion issue where I explain that even though I am not qualitatively identical with a fetus (I’m obviously a lot bigger, I have much more brain function etc), I am quite obviously numerically identical with a fetus from the past (from 1975 actually). Imagine my shock to see a philosopher contributing to a fairly prestigious encyclopedia making a mistake like this. Maybe he was having one of those days.

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As I’m in the middle of a podcast series on the nature of the mind or soul and its relation to the body or brain (or both), my interests in general have been hovering around the issue, so here’s a blog post to add to the mix.

Alvin Plantinga is one of my favourite philosophers, but when he gets it wrong, he gets it surprisingly wrong. Probably the clearest example of this is his effort to resurrect that Titanic among theistic arguments, the Ontological Argument (Titanic only in the sense of its unenviable fate, not its size). He really shouldn’t have attempted that one. But in general I think his work is the kind of thing that many aspiring Christian scholars (myself included) aspire to produce. One particular skill that he has is to paint helpful (and sometimes highly amusing) illustrations of the point that he is getting at. But every now and then I find myself thinking “what?” I’ve concluded that like many great scholars, Plantinga is brilliant in general, but he has the odd soft spot in the head, noticeable by their contrast with the rest of his head. The ontological argument is one soft spot. Another is an argument that he uses for Cartesian dualism.

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Here it is (at last!), part two of the series on philosophy of mind, In Search of the Soul. In this episode I introduce the viewpoint called emergentism, and I explore the argument for dualism from free will.

It’s not the most exciting of episodes, but it’s worth including and listening to if you’re wanting to get a decent overview of philosophy of mind because it lays out a major position (emergentism) and examines a pretty common argument for dualism. In episode 28 (I’ve decided that the whole series will be no more than five episodes long), I’ll look at William Hasker’s (among other people) objection to physicalism from the possibility of an afterlife, which I think will be a lot more interesting.

Glenn Peoples

 Episode 027: In Search of the Soul part 2 [44:34m]: Play Now | Play in Popup | Download

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Previously I have written generally favorable comments on the middle knowledge perspective on divine foreknowledge – a perspective also called Molinism. Right at the outset of this post I want to say that I still maintain that favorable stance towards that perspective. I also want to stress that this particular area of philosophy is by no means something I regard as my forte. A Middle knowledge perspective has huge appeal to me because it retains certain features that many (perhaps most) of us find intuitively attractive: Some important sense in which our choices are freely made and not wholly determined, the obvious moral responsibility for our actions that accompanies this view of freedom, a God whose knowledge is not limited by the choices we make and so who is omniscient without qualification, a God who knows not only what will happen, but who also knows how things would play out if things were different from the way they are now, and so forth.
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