# "Don't do what I tell you not to do" - what to do if you always do the opposite? [duplicate]

I'm not sure if philosophy is the right topic for this, but it's logic and language, so it kind of matches.

Me and my friend played a little game this morning where I said "don't do this and that" and he did exactly that.

Me: "Don't look around" He: looks around Me: "Don't talk gibberish" He: talks gibberish

And then I said this:

Me: "Don't do what I tell you not to do"

He said he was confused and we both laughed. But what would be the logical thing to do here? Or is there any simple logical answer to this at all?

• It's not exactly the same but there's not much we could add to the answers there. There is indeed no logical response, and the thread there shows that this (no logical response being possible) is possible, logically.
– user2953
Commented Jun 28, 2015 at 8:36

One of the reasons this doesn't quite fall under typical paradox scenarios is that your statements here are imperative statements - you're not so much presenting descriptions as much issuing instructions. Whenever you tell someone to not do something, in the rules of the game that's something they should do, so in practice you're telling them to do that thing.

Your third instruction is, properly paraphrased, a request to "do the thing that I tell you to do". You can see this by taking a sample statement (e.g. "don't turn around") and plugging it in - you tell them something that they should "not" do, and then under the rules of the game you tell them to "not" do that thing. So you're just repeating the initial instruction.

In the absence of anything else to tell them to do, then, it's not that you're issuing an impossible instruction but rather that you're issuing a vacuous instruction - you're saying "do this" with nothing for the "this" to latch on to. So giving no response is a reasonable and correct reaction.

What else might be reasonable and correct? Well that depends on what we think about the nature of your instructions. If your intent is that your friend should just try to find some action that satisfies the constraints you've set, then any action would be correct. If your intent is that your friend should try to find out the one action that you specifically intended them to do, then perhaps nothing is the only correct action.

So what do you think? Are you content that your friend should find a satisfactory response? Or would you rather they look to deduce what you were intending them to do?