(In the following, by ‘person/people’ I mean the population of both planets—or more generally any sapient beings, by ‘human’ I mean that of this planet, and by ‘human’ that of the other planet. And unfortunately I’ll have to use boldface for emphasis because italics is already used for the other purpose.)
They can answer that after parity violation was discovered, even if they could see us, and it would still be true.
They could, but they wouldn’t need to. After parity violation, they could give an actual definition by describing details of the weak interactions; and if they could see us, they could just stick out their left hand. But if someone didn’t know about P-violation and couldn’t see us, the only ‘definitions’ they could possibly give would be ones based on said contingent facts. Hence, for all beliefs of such a human about left there’s a corresponding belief of such a human about left, and vice versa, and the only things that distinguish them are outside their heads (except that the hemisphere lateralizations are the other way round than each other, but an algorithm stays the same if you flip the computer, provided it doesn’t use weak interactions.)
Is it really the case? I am not much familiar with Putnam, but I had thought that XYZ was supposed to be indistinguishable from H2O by any accessible means.
Well, if he actually specified that you couldn’t possibly tell XYZ from H2O even carrying stuff from one planet to another, then the scenario is much more blue-tentacley than I had thought, and I take back the whole “deliberately missing the point of Putnam’s experiment” thing this subthread is about. FWIW, I seem to recall that he said that there are different conditions on the two planets such that H2O would be unwaterlike on Twin Earth and XYZ would be unwaterlike on Earth, but I’m not sure this is a later interpretation by someone else.
But if someone didn’t know about P-violation and couldn’t see us, the only ‘definitions’ they could possibly give would be ones based on said contingent facts.
That’s an unfortunate fact about impossibility to faithfully communicate the meaning of some terms in certain circumstances, not about the meaning itself.
(In the following, by ‘person/people’ I mean the population of both planets—or more generally any sapient beings, by ‘human’ I mean that of this planet, and by ‘human’ that of the other planet. And unfortunately I’ll have to use boldface for emphasis because italics is already used for the other purpose.)
They could, but they wouldn’t need to. After parity violation, they could give an actual definition by describing details of the weak interactions; and if they could see us, they could just stick out their left hand. But if someone didn’t know about P-violation and couldn’t see us, the only ‘definitions’ they could possibly give would be ones based on said contingent facts. Hence, for all beliefs of such a human about left there’s a corresponding belief of such a human about left, and vice versa, and the only things that distinguish them are outside their heads (except that the hemisphere lateralizations are the other way round than each other, but an algorithm stays the same if you flip the computer, provided it doesn’t use weak interactions.)
Well, if he actually specified that you couldn’t possibly tell XYZ from H2O even carrying stuff from one planet to another, then the scenario is much more blue-tentacley than I had thought, and I take back the whole “deliberately missing the point of Putnam’s experiment” thing this subthread is about. FWIW, I seem to recall that he said that there are different conditions on the two planets such that H2O would be unwaterlike on Twin Earth and XYZ would be unwaterlike on Earth, but I’m not sure this is a later interpretation by someone else.
That’s an unfortunate fact about impossibility to faithfully communicate the meaning of some terms in certain circumstances, not about the meaning itself.