ebr4 --<livingston

T1 and T2 are different in important ways. T1 is not susceptible of empirical confirmation (or falsification) and can only be assessed in terms of its logical validity, which is presumably a matter of asking whether the different propositions it includes could all be true at the same time. If one is persuaded that no contradiction lurks in the concepts jointly employed in projecting such a scenario, it would seem reasonable to assent to T1. There is much more to be said, of course, on this subject, but Lem's insistence on a recent empirical confirmation of his forecast suggests that we should turn to T1's more robust alternative, T2.

T2 includes T1's clause about logical possibility and hence must pass the same conceptual test. But it also requires the phantomatic machine to be compatible with the laws and facts of physics, biology, and other relevant bodies of knowledge. Assuming that it is, T2 adds that at some point in time human technology will be capable of realizing the phantomatic device. The best way to show that the latter clause - and with it, the others - has been satisfied is to identify an actual instance of the successful operation of such a device.