My dog wouldn't come down the stairs today when I called, so my daughter shouted: "We're going!" which is usually sufficient to send my dog racing down the stairs. I reprimanded my daughter because she was lying (we were not going out, and it was wrong to get my dog down the stairs under false pretenses). Then I shook the keys because my dog usually comes down upon hearing the keys. Talk about casuistry! But I was wondering whether you thought it is possible to lie to a dog, and thus whether a moral issue might be involved (assume it was only my dog and I, no other humans about).Here is my suggestion: to deceive is to cause someone or something to have a false belief, intending so to do. Lying is one way to deceive. In lying one (a) affirms a falsehood, (b) believing it to be a falsehood, and (c) intending that someone believe it. There are other ways of deceiving: shaking one's keys at an adult human in order to get the adult human to believe the falsehood that one is going out, for example. I think that lying and deceit are always wrong.
I don't think, however, that a dog can have beliefs, and so I don't think that a dog can have false beliefs. In addition, one isn't usually affirming the proposition that one is going out when one says to a dog 'We're going out'; one is usually merely giving the dog a certain aural stimulus that will cause it to come down. Shaking of keys is likewise the mere conveying of an aural stimulus: there is usually, when talking to dogs, no intention that this have a causal effect by way of beliefs.
Having said all that, it seems to me likely that my friend's daughter (like most children and some philosophers) thinks of the dog as having beliefs, and so she was attempting (succesfully?) to lie to the dog. Therefore, my friend was right to castigate her. His own action in shaking the keys would, however, give his daughter the false impression that it was morally permissible to deceive -- as long as one didn't lie. So, while my friend's action was in itself morally permissible (since (I'm sure) he doesn't think that dogs have beliefs), it was ill advised in the circumstances. He should have told his daughter off, sent her out of earshot, and then done exactly what she did (but with different intentions).
What do others think?