Clearly, a thing can exist without existing here. The Washington Monument exists but not in my backyard. Accordingly, 'x exists here' can be split up as follows:
1. x exists here iff (i) x exists & (ii) x is in the vicinity of the speaker.
It seems pretty obvious that existence and the indexical property of hereness are different properties if you want to call them properties.
A much more difficult question is whether a thing can exist without existing now. Is it true that:
2. x exists now iff (i) x exists & (ii) x is temporally present?
Clearly, we can prise apart the existence of a (spatially located) thing and its hereness. Anyone who maintained that to exist = to be here we would deem either crazy or not conversant with the English language, a sort of 'local yokel' in excelsis. But can we prise apart the existence of a thing and its temporal presentness? Is there a real distinction between the existence of a thing and its temporal presentness?
A. A negative answer will be returned by the presentist who maintains that only the temporally present exists. He will maintain that what no longer exists and what does not yet exist does not now exist, and therefore does not exist at all.
Note that it ought to be is perfectly obvious to anyone who understands English that what no longer exists and what does not yet exist does not now exist. What is not at all obvious is the part after 'therefore' in the sentence before last. It is not at all obvious that an individual or event or time that is wholly past or wholly future does not exist at all.
B. An affirmative answer will be returned by all those who reject presentism. Some will reject presentism on the ground that abstracta exist, but are not in time at all, and so cannot be said to exist now. A presentist can accommodate this point by restricting his thesis:
Restricted Presentism: Necessarily, only temporally present concreta exist.
Nevertheless, the anti-presentist will insist that there are past and perhaps also future concreta that exist but do not exist now. Scollay Square, for example, no longer exists. But that it not to say that it is now nothing. After all, we still refer to it and say true things about it. It is true, for example, that my father visited Scollay Square while on shore leave during WW II on a break from service on destroyer escorts in the North Atlantic. So it is true that a a sailor who no longer exists visited a place that no longer exists and was involved in events that no longer exist. It also true that Scollay Square had been demolished by the time I arrived in Boston in 1973. I can now argue as follows:
1. Various predicates (e.g., is remembered by some Bostonians) are true of Scollay Square.
2. Scollay Square does not exist now.
3. If x does not exist, then no predicate is true of x.
4. Scollay Square exists. (From 1 and 3)
5. Scollay Square exists but is not temporally present. (From 2 and 4)
6. Restricted Presentism is false.
I think there are three ways to attack this argument: (a) reject one or more of the premises; (b) find fault with the reasoning; (c) complain that it is not clear what Restricted Presentism amounts to.
Have at it, boys.