If I have no way to do something, then it’s nonsensical to say that I should avoid doing that thing. For example, if you say that I should have avoided arriving to an appointment on time and I say that it would be impossible because you only told me about it an hour ago and it’s 1000 miles away, then it would be nonsensical for you to say that I should have avoided arriving in time anyway. This is equivalent to saying that if I should avoid doing something, then I can do it.
I don’t think this premise is as intuitive. For example, if someone said that a quadriplegic should have saved a nearby drowning child, then the objective appears immediately this it wouldn’t have been possible and so the “should” claim isn’t reasonable. On the other hand, if you say that the quadriplegic should avoid intentionally drowning the child, I don’t think that’s clearly nonsensical or false.
The analogous argument would be:
If I have no way to do something, then it’s nonsensical to say that I should avoid doing that thing. For example, if you say that I should have avoided arriving to an appointment on time and I say that it would be impossible because you only told me about it an hour ago and it’s 1000 miles away, then it would be nonsensical for you to say that I should have avoided arriving in time anyway. This is equivalent to saying that if I should avoid doing something, then I can do it.
I don’t think this premise is as intuitive. For example, if someone said that a quadriplegic should have saved a nearby drowning child, then the objective appears immediately this it wouldn’t have been possible and so the “should” claim isn’t reasonable. On the other hand, if you say that the quadriplegic should avoid intentionally drowning the child, I don’t think that’s clearly nonsensical or false.
“You should have taken every opportunity that you could to get there on time.”
“I did. I had zero opportunities to do so, and I took all zero of them.”