I hit on a tentative, succinct definition of
being yesterday, as "the indefinite
other." Using the example, "Motion
is," which had been discussed in the
Sophist seminar only a few minutes earlier, I suggested that the assertion amounts to saying that motion is other than all of the other things, but that in saying that motion
is, we don't specify the other things or the relations between motion and the other things. Someone pointed out, however, that it's possible to say that something is
other without saying that it (really)
is. Thus, "Unicorns are other than elephants" is consistent with "Unicorns are not." However, in the seminar on the
Sophist, we've already agreed there's an extended sense of
being that includes the being of nonbeing; that is, "
Nonbeing is," and "
Nonbeing is other than
being."