In 1974 Nozick asked whether you would plug into a machine that could give you any experience you desired, and he took it for granted that you would refuse.

Whether this life is a simulation is something I think we can only ever guess at, because we sit on the inside of it and the inside is all we get to check. I also think it's a moot point. Happiness is subjective, it comes down to the meaning we give to this life we're living, and we can construct that meaning in much the same way either way. Reality is a constructed concept anyway.

Robert Nozick built a famous argument on the opposite assumption. In Anarchy, State, and Utopia (Basic Books, 1974), pages 42 to 45, he asks you to imagine neuropsychologists who can give you "any experience you desired" while you float in a tank with electrodes attached to your brain. You pick your experiences two years at a time and come out every couple of years to choose again. He took it that we would refuse, and he offers that as an assumption about us with no data behind it.

He gives three reasons for refusing. We want to do certain things, over and above having the experience of doing them. We want to be a certain sort of person, and someone floating in a tank is "an indeterminate blob". The machine also confines us to a man-made reality with "no actual contact with any deeper reality".

Felipe De Brigard turned the question around in Philosophical Psychology in 2010. Undergraduates at the University of North Carolina at Chapel Hill, none with previous exposure to philosophy, read a written scenario in which they were already connected to an experience machine and were offered the choice to remain connected or go back to reality. Each student read one version, 24 per version, 72 in all.

In one version the life waiting outside was being a prisoner in a maximum security prison in West Virginia, and 87 percent of the 24 students who read that version stayed connected. In another it was being a multimillionaire artist living in Monaco, and the choice split 50/50. Described neutrally, 54 percent went back to reality. Small samples, one university, and De Brigard flags that the word reality may carry a positive tone of its own, so I hold the numbers loosely.

What stays with me is the swing. The machine was identical in all three versions, and the thing that moved was the description of the life on the other side. Those students were weighing a prison against a tank, or Monaco against a tank, and the word reality was doing far less work than Nozick's argument needs it to do.

Dan Weijers, a philosopher and senior lecturer at the University of Waikato and editor-in-chief of the International Journal of Wellbeing, said in an email that Nozick's original elicits biased judgments, mainly status quo bias, and that we can see this because tweaking supposedly irrelevant aspects of the scenario results in people choosing differently. His conclusion: "Due to these biases, Nozick's original should not be used (hence me saying it's dead... but really I suppose I'm saying it should be treated as dead)". Reversed versions like De Brigard's carry the same bias on his account, so he'd retire those too, while still wanting experience machines in use in a less biased form. His 2014 paper reports experiments to build one.

In work of his own that is unpublished and has had no peer review, he said, "people's judgments are often affected by pleasure, reality, and continuing their current relationships. This last factor seems to be the main source of status quo bias." And: "These results show that most people care about more than pleasure, and that some people care about reality, but people don't care about reality nearly as much as Nozick and others have assumed."

Nozick's third reason asks for actual contact with a deeper reality. So how would I check? Everything I could use to confirm that this world is the genuine article comes from inside this world, from my own eyes and from other people telling me they see what I see. Nozick writes that limit into his own scenario when he says that while you're in the tank you won't know that you're there. Someone in the tank, by his own design, runs the checks I run and gets the same reassuring answers back. Contact with a deeper reality is something I can believe in and have no way to inspect. So the line between the real and the manufactured can't hold the weight he put on it, because any of us could be on either side of it and feel exactly the same about our day.

Someone in the tank has handed the doing over to a program and chosen the lot two years in advance, so whatever happens in there, somebody else wrote it. That objection, and the one about being a certain sort of person, holds whether the world outside the tank is the final reality or one more layer of something else. Weijers's case, as I read it, is that these experiments mix reasons like that up with bias and can't pull them apart.

I think his unpublished point about relationships lands in the same place. If what keeps people where they are is the people they're already with, then the thing they're protecting is something they built themselves, over years, out of time and attention. That's my reading of it, and it's what I'd call meaning. It gets made from the inside, out of what you do and who you do it with.

So my answer to Nozick's question is that the meaning we build carries the happiness, and we build it out of whatever is in front of us and whoever is in front of us. I think that holds whether or not the reality we're doing it in turns out to be the deepest one there is.