> > Let's play thought experiment. If, instead of the toy-level robot pets we have today, we sometime down the road create a highly sophisticated robot pet that looks and acts just like a real dog, but with no messes, no health issues, no need to feed,and no possibility of running away or attacking somebody or what-have-you, would that still not be as good as a real dog? If not, why not?
>
> No matter how realistic you make it, some people will still feel a difference because it is not alive.

First order of business here I think would be to define some terms. First off, when I say "highly sophisticated," I mean looks and acts enough like a real dog that you wouldn't know at a glance that it was a robodog. Consider - and I don't care to argue whether or not the production of such a thing would be possible - a robodog exactly like a real dog in every respect, except that the "undesirable" features (shedding, messes, illness, etc.) did not exist. Just so people understand exactly what I'm talking about; not something roughly dog-shaped with a speaker that emits something that could maybe be considered a bark, but a robot that, if one doesn't know in advance is a robot, one would be justified in believing is a real dog.

That said, how are you defining "alive?" What is the difference in this situation between an "alive" dog and a robot dog that makes the former more desirable?

> Being living things ourselves, we tend to empathize with other things that are also living, especially if they behave in a way we can attribute to personality and character.

I'll hazard it has a lot more to do with the behaviour than you want to allow. To keep on-track here, how many people do you know who did *not* cry at the ending of Old Yeller? And (spoilers, barely) that's just a non-living representation of a real dog, too. Nobody cries because he thinks the actual dog was killed; we cry because the representation that we've come to accept as the dog - the *character* of the dog - dies. And in this case, it's not even a dog representation that anybody in the audience has ever had a personal interaction with, which seems to put it one step farther removed from reality than the robodog, and yet people still cry. Why? Because Yeller was a good dog, and he was loyal, and the characters in the film were attached to him, so therefore it was a sad situation. If they remade the movie with a pet robot instead of a gen-yoo-ine dog, I suggest (if we assume that the movie would still, you know, make any sense this way) it would have exactly the same effect on audiences.

> If a tractor is destroyed, someone might feel a sense of loss, especially if he or she has worked with that particular tractor for a very long time.
However, the feeling generally is not crushing, and if provided with another, equally capable tractor, the owner would most likely not care one way or the other. However, if a pet dies, the owner can experience a deep sense of loss, and acquiring another pet usually cannot ever fully replace the old one.

I can't say I've experienced this "crushing" feeling when a pet dies. It's sad, yes, and life goes on. But that's beside the point; your analogy fails not because of that, but because your robot-equivalent - the tractor - is nothing like an appropriate example. The tractor is a tool. That is all. It is not something that most people even have the expectation of a pet-like relationship with. I agree it's mechanical like a robot, yes, but so is the pull-tab on a can of soda, and I suggest people are still less attached to those than they would be to tractors. I also suggest that most of the sense of loss involved in the busted tractor is financial.

Pets are not tools. When a pet is lost, the feeling is not usually one of "dammit, that dog was expensive!" like it would be with a tractor.

> If your robotic dog breaks or malfunctions, you can always get another one just like it.

Not if we allow for them to be sufficiently complex, as I specified. Remember, I'm speaking hypothetically, and the "robot dogs" to which I refer would grow and change in response to their environment, just like a real dog would; it would be impossible to have one "just like" the first one because they wouldn't be raised exactly the same way.