## (ill)Logical question:

(ill)Logical question: One formulation of the law of Identity states that a thing is equal to itself (e.g., "A=A"). The "thing" must always be represented (with a letter, a word, a number, a picture, etc.) in order to be communicated. These representations will have physical, measurable properties, and no two of them -- for instance, two spoken or written "A"s -- will have exactly identical physical properties. If you attempt to circumvent this mirror image comparison with, for example, an "A" with an arrow doing a U-turn back upon itself, you still must make a mental comparison, and that comparison takes time, and as Heraclitus famously puts it, you can't step in exactly the same river twice (in other words, the first thought "A" is gone by the time you think of its twin). So, without sprawling this out further with more examples, why doesn't it make more sense to assume that "a thing is NOT equal to itself"? I am probably just talking around some hackneyed epistemological issue. Can anyone sort...

You need here the distinction between a thing and its name(s) or representation(s).

When someone says or writes "Mozart = Mozart," the two sound tokens or ink tokens are indeed subtly different. And even if somehow they were not, they would still be different in that one spoken "Mozart" precedes the other in time and one written "Mozart" is to the Southwest of the other.

But the law of identity is not supposed to be about these name tokens, but about what they refer to. That referent, the entity being named by each of these tokens, is exactly the same: the man Wolfgang Amadeus Mozart.

That it's the referents, rather than the names one has in mind here is more easily appreciated by considering an "equation" with different signs on each side. Thus consider:

Someone asserting this equation is not making the grotesque error of equating the two sound or ink tokens. Rather, she's claiming that these tokens refer to the very same thing.

## Is understanding a person (what a person does) necessarily interrelated to

Is understanding a person (what a person does) necessarily interrelated to approving of it, and is approving of it necessarily interrelated to sympathizing with it, and is sympathizing with it necessarily interrelated to identifying oneself with this person? Thanks, Susanne

Dear Susanne,

I think that you have an interesting slippery slope here. In my opinion, we should not start down it at all. We need to try to understand people and the conditions that make them the kind of people that they are. But that need not (and should not) lead to approving much less to identifying with them. We would be much better off if we tried to understand suicide bombers and pedophilic priests and the social and psychological factors that shaped them. Sympathy of a sort may be in order as well. But, approval? Not at all. Indeed, in the cases that I mentioned, part of the motivation for understanding is to try to prevent the behavior.

Lynne Baker

## Is there anything existing within or beyond the human body/mind that can be

Is there anything existing within or beyond the human body/mind that can be called "I"? If so, exactly where is "I" located?

We naturally think of the world as made up of things with properties. Take my black pen: the pen is the thing and being black is the property. But metaphysicians disagree about whether at the end of the day there are things entirely distinct from properties. Some say you need some kind of substance to have properties; others say that a pen is really just bundles of properties: its colour, weight, shape, composition, etc.

It's the same with our mental life. I have a headache: "I" is the thing, and having a headache is its property. But some philosophers would say that although we distinguish between the thought and the thinker, at the end of the day the "I" -- the thinker -- is really just a bundle of thoughts. (Insofar as it exists at all.) In that case, I suppose that the "I" would be located in the same place as those thoughts. Other philosophers may wish to insist however that the "I" must be distinct from the thoughts it has: it must be some kind of substance. It might be a physical substance or it might be a mental substance. So presumably a substance "I" would be in the same place as the body or the mind.

## A couple of years ago I read an article about an experiment where the genes of a

A couple of years ago I read an article about an experiment where the genes of a jellyfish were spliced into a rabbit - the result: a rabbit that glowed in the dark. My question is, science aside, is this a rabbit?

Good question.

I'm not sure that there's any answer "science aside", since the notion of being a member of a given biological species (in this case, some sort of rabbit) is a scientific concept. It is up to science to tell us what species are, whether there are any such things, why they arise and go extinct, and so forth.

One popular conception of a biological species is that a species is a group of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups. In other words, members of the same species form a united gene pool, so that a beneficial adaptation appearing in that pool could spread throughout it, whereas barriers prevent its spreading outside of the species.

On this view, which is obviously motivated by evolutionary considerations, the mere fact that the creature you have mentioned differs from all (other) rabbits in possessing certain genes that allow it to glow in the dark does not rule out the possibility that it is a rabbit. After all, rabbits differ from each other in a great many respects. This variation is the raw material for natural selection. Perhaps the experiment merely introduced a new sort of variation into rabbits.

On the other hand, it could be that this gene would prevent the creature from being able to interbreed with rabbits. Perhaps a rabbit would be too frightened by the glow to mate with it. Or perhaps the gene for glowing also makes the creature sterile. If so, then the creature you have mentioned would not qualify as a rabbit by the above conception of what a biological species is.

Another point: You haven't said whether the creature was returned to the wild after it was experimented upon. If not, then it belongs to no "natural population" (though it once did) and so is not a rabbit (or a member of any other biological species), by the above conception of what a biological species is. That's a tough break for zoos, don't you think?

Of course, the above definition is not the only conception of what a biological species is. However, if the creature was born from rabbits, and if its offspring would be rabbits, then it would be difficult to deny that it is a rabbit.

## What is the philosophical notion of personhood?

What is the philosophical notion of personhood? Sorry if this is a bad question. I'm new to philosophy.

One point that's implicit in Professor Pogge's answer above, but that it might be useful to make explicit, is that philosophers often use the notion of "person" in such a way that it contrasts with the genetic notion of "human". Whether or not you are human is a matter of your DNA. But whether or not you are a person cannot be settled by genetic testing. Rather, as Professor Pogge notes, it is usually taken to be a matter of having certain capacities. Thus, there may well be humans who are non-persons (for example, some philosophers have suggested that humans in persistent vegetative states fall into this category -- another controversial example concerns fetuses) and there may be persons who are non-humans (some advanced mammals, for example -- or if you want to get into the realm of science fiction, Data or Spock from Star Trek).

Specifying which capacities are necessary and/or sufficient for personhood turns out to be quite difficult. Some of the essays in Matters of Life and Death (edited by Tom Regan) give a good introduction to the issue of personhood. See in particular the essays on abortion and animal rights.

On the question of personal identity over time, John Perry's A Dialogue on Personal Identity and Immortality provides a useful introduction to the relevant issues.

## Dear Philosophers,What's it like to be another person?Milo (age 6)

Dear Philosophers, What's it like to be another person? Milo (age 6)

That's a really good question. I guess the answer is, it feels normal. Because it feels normal to them, and so if you are that person, then feeling like they do feels normal to you.

But what we really want to know is, how would it feel for me to feel what they are feeling? If I could "see" what a red apple looked like to them, would it look red to me? Or would it look green? If I could feel their sleepiness, would it feel like mine? Fortunately, Milo, philosophers have thought long and hard about this question. Unfortunately, we haven't figured it out yet. What do you think?

## Some years ago I heard one of the Beatles in the course of a conversation about

Some years ago I heard one of the Beatles in the course of a conversation about his career opine that 'after all I might easily have been someone else, mightn't I'. I remember not being sure about this proposition. One half knows what is being got at but on the other hand, it seems barely intelligible. Could I easily have been someone else? Ian g

Several years ago, in a fit of anger at her father, my daughter turned her anger on me and demanded that I explain to her why I had ever gotten involved with him. I pointed out to her that she had no right to be angry at me on these grounds, since she wouldn’t have existed had it not been for my involvement with him. Her origins are essential to her, and she wouldn’t have existed had it not been for these origins. Might she then have reasonably replied that she could have been someone else? I agree that this claim is barely coherent. It is true that she could have had many different attributes. She might not have developed certain interests; she might not have looked exactly the way that she looks. But that’s not to say that she could have been someone else; it’s to say that she– the very same person– could have had certain different attributes. For further thoughts that are relevant to this question, see 302 and 433.

## How do formal logicians respond to Marxist/Leninist/Dialectical logic claims?

How do formal logicians respond to Marxist/Leninist/Dialectical logic claims? For example, in "An Introduction to the Logic of Marxism", George Novack explains that the law of identity of formal logic, that "A is equal to A", is always falsified when we try to apply it to reality. Here is a quote from the book, in which he quotes from "In Defense of Marxism" (it is long, I apologize): "... a pound of sugar is equal to itself. Neither is this true -- all bodies change uninterruptedly in size, weight, color, etc. They are never equal to themselves. A sophist will respond that a pound of sugar is equal to itself at 'any given moment.' "Aside from the extremely dubious practical value of this 'axiom,' it does not withstand theoretical criticism either. How should we really conceive the word 'moment'? If it is an infinitesimal interval of time, then a pound of sugar is subjected during the course of that 'moment' to inevitable changes. Or is the 'moment' a purely mathematical abstraction, that is, a...

According to a standard conception of identity, if A is identical to B, then A and B haveall of their properties in common. This principle is commonly known asLeibniz’s law, after the philosopher Gottfried Wilhelm Leibniz, a 17thcentury German philosopher, who articulated this implication of ourconcept of identity. This principle is also referred to as "theprinciple of the indiscernibility of identicals". This law or principlemight seem to imply that if a particular object (say a particularquantity of sugar) changes over time, then it’s not the same thing–after all, the properties of the object at one time are different fromthe properties of that object at another time. However, this reasoningrests on a confusion. Leibniz’s law does not imply that if A at T1 has properties f, g, and h, then A at T2 must have these same properties. Instead, it implies that, if it is true of A that at T1 it has properties f, g, and h, then at T2 it is true of A that at T1 it had properties f, g, and h.

## You have no doubt heard this example of the problem of identity before, but bear

You have no doubt heard this example of the problem of identity before, but bear with me. Say you are given an axe for your birthday. Upon using the Axe on a length of wood you smash the axe head on a rusty bolt. You venture to get another Axe head from your local hardware store, return home and replace the damaged part with the new. Upon striking the wood a second time you consciously avoid the bolt to no avail as now the Axe handle shatters. You, for a second time, venture to the hardware store to get a replacement handle, return home and install it. Now, the question you probably saw coming is – is this still the Axe you were given for your birthday? I say yes, because you attached the replacement parts with respect to its original condition, not with intent to modify or improve. The deeper problem with saying that, indeed, the Axe SHOULD now be considered a different Axe is that the human body replaces all its atoms every 7 years (or so), yet nobody says that we are doppelganger (many times over)...

## If I am made up of countless organisms, who is experiencing the independent

If I am made up of countless organisms, who is experiencing the independent thoughts?

*You* are. You, the person, are the subject of your thoughts; you are the one whose thoughts they are. The countless organisms you mention make up one big organism--the human organism that constitutes you. It seems to me a mistake to think that your brain is the subject of thought. Your brain is the organ by means of which you think, just as your legs are the limbs by means of which you walk.

There is a divide in philosophy (even today) among those who think that a subject of thought is immaterial (e.g., Plato, Descartes and his intellectual descendants) and those who think that subjects of thought can be fit into the material world (e.g., many who work in the sciences). It's really an interesting question. It seems to me reasonable to argue that subjects of thought are truly special--different in kind from other sorts of beings in the universe--and at the same to to deny that subjects of thought are immaterial. But, of course, many disagree!