Actualist and Presentist Ersatzism and Arguments Against Both

For the actualist, the actual alone exists: the unactual, whether merely possible or impossible, does not exist.  The actualist is not pushing platitudes: he is not telling us that the actual alone is actual or that the merely possible is not actual.  'Merely possible' just means 'possible but not actual.' The actualist is saying something non-platitudinous, something that may be reasonably controverted, namely, that only the actual exists: the merely possible and the impossible do not exist.

Analogously for the presentist.  For the presentist, the (temporally) present alone exists: the nonpresent, whether past or future, does not exist.  The presentist is not pushing the platitude that the past is no longer.  He is saying something stronger: the past is not at all.

For the actualist, then, the merely possible does not exist.  There just is no such item as the merely possible fat man in my doorway.  Nevertheless, it is true, actually true, that there might have been a fat man in my doorway.  (My neighbor Ted from across the street is a corpulent fellow; surely he might have come over to pay me a visit. 'Might' as lately tokened is not to be read epistemically.)    The just-mentioned  truth cannot 'hang in the air'; it must be  grounded in some reality.  To put it another way, the merely possible -- whether a merely possible individual or a merely possible state of affairs -- has a 'reality' that we need somehow to accommodate.  The merely possible is not nothing.  That is a datum, a Moorean fact.

Similarly, it is true now that I hiked yesterday, even if presentism is true and the past does not exist.  So there has to be some 'reality' to the past, and we need to find a way to accommodate it.  Yesterday's gone, as Chad and Jeremy told us back in '64.  Gone but not forgotten: veridically remembered (in part) hence not a mere nothing.  That too is a datum.

The data I have just reviewed are expressed in the following two parallel aporetic tetrads, the first modal, the second temporal.

Modal Tetrad

1. The merely possible is not actual.
2. The merely possible is not nothing.
3. To exist = to be actual.
4. To exist = not to be nothing.

Temporal Tetrad

1t. The merely past is not present.
2t. The merely past is not nothing.
3t. To exist = to be present.
4. To exist = not to be nothing. 

Each tetrad has limbs that are jointly inconsistent but individually plausible. Philosophical problems arise when plausibilities come into logical conflict.  The tetrads motivate ersatzism since the first can be solved by adopting actualist ersatzism (also known simply as actualism) and the second by adopting presentist ersatzism.  (Note that one could be a presentist without being an ersatzer.)

The ersatzer solution is to deny the first limb of each tetrad by introducing substitute items that 'go proxy' for the items which, on actualism and presentism, do not exist.  These substitute items must of course exist while satisfying the strictures of actualism and presentism, respectively.  The substitute items must actually exist and presently exist, respectively.  So how does it work?

The actualist maintains, most plausibly,  that everything is actual.  But the merely possible must be accommodated: it is not nothing.  The merely possible can be accommodated by introducing actually existent abstract states of affairs and abstract properties.  Merely possible concrete states of affairs are actual abstract states of affairs that do not obtain.  Merely possible concrete individuals are abstract properties that are not instantiated.  Suppose there are n cats.  There might have been n +1.  The possibility of there being in concrete reality n + 1 cats is an abstract state of affairs that does not obtain, but might have obtained.   Suppose you believe that before Socrates came into existence there was the de re possibility that Socrates, that very individual, come into existence.  Then, if you are an actualist, you could accommodate the reality of this possibility by identifying the de re possibility of Socrates with an actually existent haecceity property, Socrateity.  The actual existence in concrete reality of Socrates would then be the being-instantiated of this haecceity property.

Possible worlds can be accommodated by identifying them with maximal abstract states of affairs or maximal abstract propositions.  Some identify worlds with maximally consistent abstract sets, but this proposal faces, I believe, Cantorian difficulties.  The main idea, however, is that possible worlds for the actualist ersatzer are maximal abstract objects.  Now one of the possible worlds is of course the actual world.  It follows immediately that the actual world must not be confused with the concrete universe.  It may sound strange, but for the actualist ersatzer, the actual world is an abstract object, a maximal proposition.

The actualist, then, rejects (1) and replaces it with

1*.  A merely possible concrete item is an actual abstract object that possibly obtains or possibly is instantiated or possibly is true.

The presentist ersatzer does something similar with (1t).  He replaces it with

1t*.  A merely past concrete item is a temporally present abstract object that did obtain or was instantiated or was true or had a member.

An Argument Against Actualist Ersatzism 

Let's examine the view that possible worlds are maximal abstract propositions.  If so, the actual world is the true maximal proposition, and actuality is truth.  Given that there is a plurality of worlds, whichever world is actual is contingently actual.  So our world, call it 'Charley,' being the one and only (absolutely) actual world, is contingently actual, i.e., contingently true.  Contingent affirmative truths, however, need truth-makers.  So Charley needs a truth-maker.  The truth-maker of Charley  is the concrete universe as we know it and love it.  Since actuality is truth, the concrete universe is not and cannot be actual.

So the concrete universe exists but is not actual!  But this contradicts (3) above, according to which existence is actuality.  The actualist ersatzer is committed to all of the following, but they cannot  all be true:

5. Actuality is truth.
6. Truth is a property of propositions, not of concreta or merelogical sums of concreta.
7. The concrete universe is a concretum or a sum of concreta.
8. Everything that exists is actual: there are no mere possibilia or impossibilia.
9. The concrete universe exists.

This is an inconsistent pentad because any four of the limbs, taken together, entails the negation of the remaining one.  For example, the conjunction of the first four limbs entails the negation of (9).

Curiously, in attempting to solve the modal tetrad, the actualist embraces an inconsistent pentad.   Not good!

An Argument Against Presentist Ersatzism

A parallel inconsistent pentad is easily constructed.  The target here is the view that times are maximal propositions.

5t. Temporal presentness is truth.
6. Truth is a property of propositions, not of concreta or merelogical sums of concreta.
7. The concrete universe is a concretum or a sum of concreta.
8t. Everything that exists is present: there are no merely past or merely future items. 
9. The concrete universe exists.

One sort of presentist erstazer is committed to all five propositions, but they obviously cannot all be true. 

Related articles

Times as Maximal Propositions

Presentism and Actualism, Tenseless Existence and Amodal Existence

Presentism Between Scylla and Charybdis

Abstracta: Omnitemporal or Timeless? An Argument from McCann

Can a Thing Exist Without Existing Now?

Still Puzzling Over Presentism

Defining Presentism

Comments

[David Brightly]

Hello Bill,

Convincing arguments against the ersatzisms. What I don't understand is why the actualist or presentist need find himself in such a tight corner that he turns to the desperate measure of conflating concrete and abstract. For the actualist can object to your (2), claiming it has the wrong mood and should be expressed as

The merely possible might not be nothing, ie, might be something.

Likewise, the presentist can object that (2t) is wrongly tensed. It should say

The merely past was not nothing.

Both tetrads are then consistent.

[Bill Vallicella]

Hi David,

I'm glad to see there's still some interest in this topic.

>>The merely possible might not be nothing, ie, might be something.<<

That is not strong enough. 'Possibly, I am asleep now.' That sentence is actually true, not merely possibly true.

>>The merely past was not nothing.<<

That's true, but it is not strong enough. True, the Profumo scandal (1963) was not nothing. But it also is not nothing. It has some sort of reality even though it is wholly past. Apparently, you don't share this intuition, and I'm wondering why not.

[David Brightly]

Hello Bill,

I'm an anomalous trichromat. I think of normal colour vision as a rather finer grained version of my own, with, as it were, more 'places'. I understand what category of experience is denied me. My difficulty with anti-presentism is that I can't locate a 'place' for it in my intuitive geography. I appear to be denying something without any appreciation of what it is that I'm denying.

I agree that 'Possibly, I am asleep now' is actually true, not merely possibly true, but I'm afraid I can't connect this to what I'm saying about using the subjunctive.

I'm not asleep now though I might be. Hence my being asleep now must be numbered among the merely possible. I would render this as

my being asleep is not but might be,

a true conjunction of the indicative and subjunctive. I'm at a loss to see how this can be made stronger without falling into the falsehood of

my being asleep is.

So again I seem to lack the 'place' where you are standing.

[Bill Vallicella]

David,

I am not asleep now & possibly, I am asleep now.

What would you say is the truth-maker of the second conjunct?

[David Brightly]

The lack of anything that necessitates my being awake now.