1519 - One Dual-Config Robot or Two Robots?

[Tristan Lall]

Originally Posted by Ken Streeter

Consider two vehicles for sale at your local Ford dealer: a Ford Escape and a Ford Focus. Let's say you purchase these two vehicles and bring them home with you. After getting them home, you take the engine out of the Focus and have the engine recycled for scrap steel. Now, whenever you want to commute to work you pull the engine out of the Escape and stick it in the Ford Focus. When the weekend arrives and you want to go offroading, you pull the engine again and stick it into the Escape. Do you have one vehicle, or two? Sure looks and feels like two vehicles to me!

Continuing the thought experiment, it seems necessary that we examine our definition of a vehicle. There's an argument to be made that if we don't rely on our preconceived notion of what a Ford is, then we might find that our system satisfies all of the criteria placed upon it, even though it is, to the casual observer, two vehicles.

Consider an alternative case: say we have the Escape, and we buy all of the parts needed to assemble a Focus, except the engine. Initially, by all accounts, we possess a vehicle and a pile of parts. Then, we remove the engine from the Escape, and start bolting Focus parts on to it. At this point, we have a vehicle without an engine (is that still a vehicle?), and a pile of parts. At what point do we declare that we no longer have a pile of parts, and instead have a Ford Focus? That's the problem here: the robot definition doesn't specify how we might make that decision. To the outside observer, while the appearance of two robots or two vehicles may seem self-evident, in reality, the robot construction process more closely approximates this procedure, and, in my opinion, ought to be treated as such.