 Adams’ break with Prior on this point is semantic, not metaphysical. Specifically, over and above the notion of truth in a world defined above, Adams identifies a second notion of truth relative to a world that he calls truth at a world. The difference between the two is one of perspective, a difference in what we might call the evaluative standpoint. The propositions that are true in a world \(w,\) recall, are those that are members of \(w\); hence, intuitively, they would all have existed had \(w\) obtained. They are thus the propositions that can be recognized as true from a standpoint “within” \(w\)—since they would have existed if \(w\) had obtained, an agent with sufficient cognitive powers (we can imagine) that might have existed if \(w\) had obtained could have grasped and evaluated them. However—and this is Adams’ crucial insight—from her perspective in \(w,\) that same agent can also evaluate propositions in \(w\) with respect to other worlds \(u\)—notably, for any individual \(x\) in \(w,\) she can see that the proposition \(\neg \sfE!\sfx\) that \(x\) doesn’t exist rightly characterizes any \(x\)-free world \(u,\) the absence of the proposition in question in \(u\) notwithstanding. The proposition is thus, from the standpoint of \(w,\) said to be true at, but not in, \(u\). As Adams, here in the actual world, puts it with regard to the proposition \(\neg \sfE!\sfa\) that he doesn’t exist: