The Cucumber Curse: A Platonic Dialogue by MC Complete

Daniel: What do you think about Frank Jackson’s Mary’s Room argument?

Bob: I don’t think Mary learns anything when she leaves the room.

Daniel: She learns what seeing colors is like, doesn’t she? She learns what seeing blue is like, she learns what seeing red is like...

Bob: What blue “is like” is not information.

Daniel: What do you mean?

Bob: Well, what is it like to see blue? Why don’t you tell me?

Daniel: You already know.

Bob: But if I didn’t, there wouldn’t be any way to communicate it to me.

Daniel: I could show you something blue.

Bob: I mean, if you couldn’t show me something blue, for whatever reason, there’s no way you could communicate to me what it’s like. What is it “like” to see blue? The answer to that question can’t be communicated, because it can’t be encoded. All the information about vision and experience is encodable, and it presumably is encoded, in our brains.

Daniel: That makes sense. I can see why you’re not convinced by Mary’s Room. I have another story, though. You could call it a variation on Mary’s Room.

Bob: Do you have a name for it?

Daniel: No. I guess you could call it The Cucumber Curse. The story is about Bob.

Bob: Bob? He sounds intelligent. Is he a neuroscientist like Mary?

Daniel: No, he’s a philosopher. A materialist, in fact.

Bob: Like most philosophers of our day.

Daniel: The trouble starts when he’s late for a lecture. On his way to the university, he cuts off another car, kind of accidentally, kind of not so accidentally. Unfortunately for Bob, the driver of the car that he cut off was The Wicked Witch of Western Philosophy. The witch goes into a fit of rage and puts a curse on Bob. Suddenly, all cucumbers start to look red.

Bob: That’s interesting. And celery is still green?

Daniel: Yes, everything green but cucumbers.

Bob: And for everyone else, the cucumbers are still green?

Daniel: Yes, for everyone else.

Bob: Well, apparently something in Bob’s brain is scrambling the color signals. Something sophisticated enough to know what is a cucumber and what isn’t.

Daniel: Well, that’s what Bob thinks at first, but then he looks over his brain logs and sees that his neurological state when looking at cucumbers is the same as his neurological state when looking at celery.

Bob: His brain logs?

Daniel: You see, Mary has invented a device which produces something like a debug log of the brain, capturing all its states and transformations.

Bob: Clearly, there’s something that these brain logs are missing. This calls for more research.

Daniel: Look, just assume that these brain logs are not missing anything, OK? The neurological state is the same, but cucumbers are red and celery is green.

Bob: So there’s a mismatch between the brain and the mind.

Daniel: Yes. The brain state of cucumber is the same as the brain state of celery, and different from the brain state of beets. However, the mind state of cucumber is the same as that of beets and different from that of celery. I agree, “green is greenish” is not information. However, “cucumbers look like beets” is information, and a description of the world that only takes matter into account loses this information.

Bob: So you’d like to draw the conclusion that, in the real world, the information “cucumbers are the same color as celery” and “cucumbers produce the same brain state as celery” are two different propositions, even though in the real world, a given brain state always corresponds to a single color.

Daniel: Yes. The information is not what green “is like”, but that green is like something. This is information that Mary knows before she leaves her room, even though she’s never experienced it. It is information that is missing from a materialist description of the world.

Bob: Very clever. However, I’m suspicious of thought experiments that resort to the supernatural. I mean, even a dualist would admit that this scenario goes against the laws of physics, as the dualist takes them to be.

Daniel: Well, in dualist physics, brain states cause mind states, but a given mind state can be influenced by a previous mind state as well as by the brain state. But you’re probably right that the cucumber story is pure fantasy even for a dualist.

Bob: In fact, it seems intuitively that such a story must break the laws of physics, even dualist physics.

Daniel: I don’t think so. I have another story.

Bob: Do tell.

Daniel: You’ll have to wait for my next blog post.

Bob: I can’t wait.