Category: Time and Change

A-Eternalism and B-Eternalism

In an earlier thread, I raised the following problem for eternalism:

Long ago, in ancient Rome's Coliseum, gladiatorial battles took place. No one will say that such battles are still going on, or that any such battles are occurring at present. But if eternalism is true, and a past gladiatorial battle is as real/existent as a present battle in the Ukraine, say, except that the first occurs at an earlier temporal location than the latter, then it seems that the gladiatorial battles are tenselessly occurring — which is highly counterintuitive.

Suppose time travel is possible. Suppose we travel back in time to the gladiatorial battles in the Coliseum. Will we find slaughter going on there? If so, then the name 'eternalism' will be most apt: the slaughter will continue eternally. But this is highly counterintuitive!

Malcolm Pollack responded:

Well, there's the problem for eternalism, as I've noted before: it offers no explanation for the subjective experience of time's passage; for why the fundamental fact of our experience is a succession of "nows" that come and go; for the sequential privileging of small (but not infinitesimal!) slices of M [the four-dimensional manifold of events/spacetime points] as "now". I think it must be connected deeply, or even somehow identical with, that other titanic mystery, namely that of consciousness.

But the problem I am raising is different.  It arises whether or not we bring consciousness into the picture.  We will be able to appreciate the difference between Pollack's problem and mine if we distinguish between two types of eternalism, A-eternalism and B-eternalism.

A- and B-eternalism both reject the presentist restriction of what exists*, i.e. what exists simpliciter, to what exists (present-tense). Thus both types of eternalist hold that past, present, and future items exist*. The two positions agree as to temporal ontology: they agree about what there is in time.  The ontological question, Quine famously said, is the question formulable in three Anglo-Saxon monosyllables: What is there?  So the temporal-ontological question is: What is there in time? On this question, both types of eternalist agree.

The two types differ, however, in that the A-eternalist accepts that there are such irreducible non-relational properties as presentness, pastness, and futurity – the so-called A-properties – whereas the B-eternalist denies that there are any A-properties: there are only the B-relations. Thus the two types of eternalist differ over the nature of time, but not over what there is in time.  The A- and B-eternalists differ over the nature of time in that they differ over whether real time, time as it is in mind-independent reality, is exhausted by the B-series, the series of events ordered by the dyadic B-relations, earlier than, later than, and simultaneous with. The B-eternalist says that real time is exhausted by the B-series. The A-eternalist demurs: there are, in addition to the B-relations, the A-properties, the monadic or non-relational properties of presentness, pastness, and futurity.

The A-eternalist is equipped to admit the non-subjective passage of time. Temporal passage is real  independently of our subjective time-conscious inasmuch as it consists in the shifting exemplification of  the monadic (non-relational) A-properties by the events in the B-series. Consider, for example, three events/processes: my birth, my present blogging, and my death.  My death exemplifies the property of being future but will soon enough lose that property and come to exemplify the property of being present, after which it will come to exemplify the property of being past, and then ever more past.  My present blogging — the blogging of this very post — will become past and ever more past. My birth which is now past will become ever more past.  The three events themselves are 'eternal' in the somewhat strained sense of existing, though not occurring, at every time.

The A-eternalist's admission of A-properties allows for the real separability of temporal presentness from existence. This allowance in turn allows for a 'moving spotlight' theory of time according to which temporal passage is real (and thus neither merely apparent nor illusory). So when I die I lose the purely temporal property of being present but I remain in existence* and come to acquire the purely temporal property of being past.  When I die I will 'move away' from the present by becoming wholly past and ever more past. Or you could think of the 'moving spotlight' of the Now moving forward and leaving me 'in the dark,' i.e., non-present. Non-present but not non-existent*!

In sum, on A-eternalism, temporal passage is real and non-subjective, hence neither merely apparent nor illusory (as the great McTaggart thought).

Philosophy and Science: Continuity or Discontinuity? Presentism Meets Physics

Malcolm Pollack writes,
 
I hope you'll forgive me for hammering you with emails, but I just wanted to thank you for inviting me to join you in giving this paper a careful going-over. [Christian Wuetrich, "The Fate of Presentism in Modern Physics" in New Papers on the Present, Philosophia Verlag, 2013, 91-131. ] It has given me, as a civilian, yet another opportunity to appreciate the care and attention to detail that professionals in your field must bring to their work. I was struck in particular by this paragraph, from section 3:
 
  "The acceptance of a conflict between presentism and not only SR [Special Relativity], but all of current, as well as prospective, fundamental physics paired with an insistence on presentism amounts to a rather comprehensive rejection of physics. It thus fundamentally contravenes naturalism, a venerable tradition going back at least to Aristotle. According to naturalism, philosophical—and metaphysical—inquiry is continuous with scientific inquiry. To be sure, naturalism is not a logical truth—it is a substantive philosophical thesis. But it is one whose defence has to wait for another day; for present purposes, I simply assume a minimal naturalism which demands that no philosophical thesis be in manifest contradiction to facts established by our best science. Restricting this weak thesis to metaphysics, it can be translated as necessitating that the physically possible worlds are a subset of the metaphysically possible ones, for if the metaphysical theories were in contradiction to the physical ones, then there would have to be some physically possible worlds (and perhaps all) which are metaphysically impossible, as for the metaphysical theory to be incompatible with physics, it would have to rule out some physically possible worlds as impossible. In other words, metaphysics would a priori deem impossible what physics affirms is possible. Assuming that all physically possible worlds are also logically possible, I see little justification for disavowing this weak form of naturalism." 
 
I find this precision, clarity, and style delightful entirely on its own, quite apart from any conclusions it may be leading to. Much obliged.
 
Malcolm,
 
I thank you in return for giving me the opportunity to achieve clarity on these topics in connection with a book on metaphilosophy I must finish before the Grim Reaper (Benign Releaser?) lops my head off.   As a chess player you know what it is like to be in time trouble with Sudden Death looming, except that it this case it is a scythe and not a flag that will fall.  And what the fall will end won't be a mere game.
 
I will begin by listing some of the main points in W's article, clarifying the key terms, and formulating some of the issues that arise.  Ask any questions or make any objections that occur to you. If you find anything I say less than clear, say so.  Double quotes mean that I am literally quoting the author. For all other purposes I use single 'quotes.' (One of those uses is instanced in the immediately preceding sentence.) Numbers in parentheses are page references.
 
1) The author is committed to thinking of time as spacetime, a four-dimensional manifold M composed of "points."  (92) These are spacetime points or temporal locations specifiable by x, y, z, and t coordinates, where a spacetime point is a punctuate (duration-less) instant.  I take it that M is a continuum so that, between any two instants, or temporal locations, there are continuum-many (2-to-the-alepth-null) instants or temporal locations. This assumes Cantorian set theory and the actual (as opposed to potential) infinite.  But then  on the same page, he speaks of "events."  As I see it, an event is not the same as the time(s) at which it occurs.  (The occupant of a spatiotemporal location is not the same as the location it occupies.) I should think that there are times when nothing happens, i.e., when no event occurs,  but that whenever an event occurs it must occur at a time or over times.  The same goes for spacetime points. Some are unoccupied by physical events, no? An event that is not punctuate like an instant I call  a process, even it it lasts only a nanosecond. Nanoseconds and related terms pertain to the "metric" which applies to M. (92)  An example of a process, i.e., an extended event, is a storm or a melody.  A side point worth pondering is that the universe, supposing it began to exist with a Big Bang, could be metrically finite (12 or so billion years old) despite M's having the cardinality of the continuum, which implies that there are continuum-many events/times between now and the Big Bang
 
One of the issues that arises here, one not discussed by W., is whether concrete things such as the piano on which the melody is played can be "assayed" (technical term of Gustav Bergmann with mining provenience) as extended events or processes. If so, then pianos and piano players have temporal parts in addition to spatial parts — a view vehemently denied by many philosophers.  A melody is not wholly present at every time at which it exists; is the same true of Billy Joel? Melodies and storms unfold over time; they have phases. Do persons unfold over time? Is a person a diachronic collection of person-phases? A person persists through time, no doubt — 'persists' is a datanic term  in my lexicon — but does he persist by enduring or by perduring? Is a person or a concrete thing/substance wholly present at every time at which it exists or not? This question goes to the back burner.
 
2) Given the fundamental presupposition that time is in reality spacetime, eternalism and presentism are defined by the author as follows. Eternalism is "the position claiming physical existence for all events in M," whereas presentism "partitions events into past, present, and future events" together with the proviso  that only the events belonging  to the present partition enjoy ontological privilege. (92) "Thus the sum total of physical existence is a proper subset of that according to the eternalist." (92)
 
This I find less than clear. What does the author mean by physical existence? As opposed to what? Surely not mental or abstract/ideal existence.  Does he mean the existence of events at times, as opposed to the times at which they exist?  An event is not the same as the spacetime point or points at which it occurs.  Is it not obvious that the occupant of a location, whether spatial or temporal or spatiotemporal, is not the same as the location? A location exists just as well occupied as unoccupied. Does the author mean to tell us that events exist physically but that times, though they exist, do not exist physically?
 
Connected with this lack of clarity is the following objection. Presentism is usually explained as the view that temporally present items (whether times or events or members of other categories) alone exist, and thus that wholly past items and wholly future items do not exist, where 'wholly' rules out overlap with the present.   If that is what is meant by presentism, then W. hasn't captured it in his definition.  For if present items are a proper subset of all existing items (spatiotemporal locations  and events at those locations) then those past and future items also exist. But then we are no longer talking about presentism.  Presentism is precisely the denial of the existence of the past and the future. The author appear to be begging the question in favor of eternalism by assuming that eternalism is true and that presentism can be defined in terms of it.  This ignores the fact that eternalism and presentism are mutually exclusive.
 
If presentism is the logical contradictory of eternalism, then what exists according to presentism cannot be a proper subset of what exists according to eternalism.  The author my be fudging the issue with his obscure talk of physical existence.
 
3) We were told that presentism partitions M into past, present, and future events.  Now what makes present events present? Here is where simultaneity comes into the picture.  Simultaneity is an equivalence relation (reflexive, symmetrical, transitive) that effects the partition that creates a proper subset of events, the present ones, and distinguishes them from those to their past and those to their future.  This puzzles me for a couple of reasons which I will sketch now, and try to explain more clearly tomorrow.
 
First, the present as we experience it is not punctuate but specious, in William James's sense of 'specious.' It has a certain spread or duration.  'Now' in 'The sun is now rising' picks out a short period of time that had not yet begun when the sun was below the horizon and will be over a short time later, say in an hour. Sunrise is not an instantaneous event by a a process.
 
Second, how does what the author says distinguish the present present from past and future presents? After all, at every time or temporal location t in M there is an equivalence class of simultaneous events at t. It follows that there are many — continuum-many! — presents, each equally present at itself.  The present present, however, is not merely present at itself, but present simpliciter. It is the 'privileged present,' the absolute present.  Presentism is committed to an absolute present. So again, it seems that our author has not put his finger on what privileges the present present, and distinguishes it from past and future presents.
 

John Bigelow’s Lucretian Defense of Presentism, Part I, Set-Up

What follows in two parts is a critique of John Bigelow's Presentism and Properties. This installment is Part One.

Bigelow begins by telling us that he is a presentist: "nothing exists which is not present." (35) He goes on to say that this was believed by everyone, including philosophers, until the 19th century. But this is plainly false inasmuch as Plato maintained that there are things, the eidē, that exist but are not present, and this for the simple reason that they are not in time at all. Moreover, many theologians long before the 19th century held that God is eternal, as opposed to omnitemporal, and therefore not temporally present. (To underscore the obvious, when presentists use 'present' they mean temporally present, not spatially present or present in any other sense.)

But let's be charitable. What Bigelow means to tell us is that nothing exists in time that is not present.  His is a thesis in temporal ontology, not in general ontology. What is there in time? Only present items, which is to say: no wholly past or wholly future items. 

Bigelow also assures us that presentism "is written into the grammar of every natural language . . ." (ibid.) But this can't be right, for then anyone who denied presentism would be guilty of solecism! Surely 'Something exists which is not present' is not ungrammatical.  The same holds for 'Something exists in time which is not present.' There is nothing ungrammatical in either sentence. If presentism "is written into the grammar of every natural language," then presentism reduces to a miserable tautology.

Tautologies, however, though of logical interest, are of no metaphysical interest. Luckily, Bigelow contradicts himself on the very next page where we read, "Presentism is a metaphysical doctrine . . . ." That is exactly right. It therefore cannot be a logico-grammatical truth.  It is a substantive, non-tautological answer to a metaphysical/ontological question about what there is in time:  only present items, or past, present, and future items?

What has to be understood is that, when a presentist claims that nothing exists that is not present, his use of 'exists' is not present-tensed, but tense-neutral.  His claim is that only what exists (present-tense) exists  simpliciter.   For present purposes (pun intended), an item or category of item exists simpliciter if it must be mentioned in a complete inventory of what there is.  I will use 'exists*' to refer to existence simpliciter and 'exists' in the usual present-tensed way.

Can presentism thus understood be refuted? 

The argument from relations

1) All relations are existence-entailing. In the dyadic case, what this means is that if x stands to y in the relation R, then both x and y exist*, and necessarily so.  In the n-adic case, it means that all of the relata of a relation must exist if the relation is to hold or obtain. 

2) Some relations are such that they hold between a non-present item and a present item.  For example, my non-present birth is earlier than my present blogging.  The two events are related by the earlier-than relation.

Therefore

3) Both events, my birth and my blogging, exist*.

Therefore

4) It is not the case that only present items exist*: presentism is false.

This is a powerful argument, valid in point of logical form, but not absolutely conclusive, or as I like to say, rationally coercive, inasmuch as (1) is open to two counterexamples:

a) If there is a relation that connects an existent item to a nonexistent item, then (1) is false. Some hold that intentionality is such a relation.  Suppose Tom, who exists, is thinking of Pegasus, who does not exist.  For details, see The Twardowski-Meinong-Grossmann Solution to the Problem of Intentionality.

b) Premise (1) is also false if there are relations that connect one nonexistent item to another nonexistent item. It is true that Othello loves Desdemona.  The truth-maker here is a state of affairs  involving two nonexistent individuals. So a Meinongian might argue that not all relations are existence-entailing, and that (1) can be reasonably rejected, and with it the argument's conclusion. (See pp. 37-39)

To sidestep the second counterexample, Bigelow proposes a weaker premise according to which relations are not existence-entailing but existence-symmetric.  A relation is existence-symmetric iff either all its relata exist or all do not exist.

The argument from causation

Causation is existence-symmetric: if an event exists and it is a cause of some other event, then that other event exists; and if an event exists and is caused by some other event, then that other event exists. Some present events are caused by events that are not present. And some present events are the causes of other events which are not present. Therefore things exist which are not present. (p. 40)

How can presentism be upheld in the face of these two powerful arguments? That is the topic of Part II.

A ‘Temporal’ Argument Against Race Change

The following excerpt is 'cannibalized' from my Substack article, Can One Change One's Race?

…………………

Can I change my race? No. I can no more change my race than I can change the fact that I was born in California.  I might have been born elsewhere, of course, but as a matter of contingent fact, I am a native Californian.  Despite the logical contingency of my California birth, there is nothing I or anyone, including God, can do, or could have done, after the fact, to change or annul that fact about my place of birth.  And there is nothing I or anyone can do, or could have done, after the fact, to alter my place of birth, time of birth, weight, or any other contingent detail.

The same goes for race. My race is determined by my biological ancestors. Since both were white, I am white.  To change my race I would have to change a past fact, namely, that I am the product of the copulation of two white parents. But that fact, being past, cannot now be changed or annulled. The argument, then, is this:

1) If I can change my race from white to black, say, then I can change some fact in the distant past, namely, the fact that I am the offspring of two white parents;

2) It is not the case that I can change any past fact including the fact that I am the offspring of two white parents;

Ergo

3) It is not the case that I can change my race.

The argument assumes that it is nomologically necessary (necessary given the laws of nature) that parents of the same race have offspring of the same race, that, e.g., white parents have white offspring. The assumption is obviously true. 

The Ersatz Eternity of the Past: Denied by Lukasiewicz!

The Pole denies the actuality of the past and in consequence thereof the ersatz eternity or accidental necessity (necessitas per accidens) of the past.

Quasi-literary Preamble:

What has been, though it needn't have been, always will have been.  What time has mothered, no future time can destroy.   What you were and that you were stand forever inscribed in the roster of being whether or not anyone  ever reads the record.  What you have done, good or bad, and what you have left undone, good or bad, cannot be erased by the passage of time. You will die, but your having lived will never die. This is so even if you and your works and days are utterly forgotten. An actual past buried in oblivion remains an actual past. The erasure of memories and memorials is not the erasure of their quondam objects. The being of what was does not depend on their being-known; it does not rest on the spotty memories, flickering and fallible, of fragile mortals or their transient monuments or recording devices.

But how paltry the ersatz eternity of time's progeny!  Time has made you and will unmake you.  In compensation, she allows your having been to rise above the reach of the flux.  Thanks a lot, bitch!  You are one mater dolorosa whose consolation is as petty as your penance is hard.

………………………….

I posted a precursor of the above on 10 March 2010.  It elicited an astute comment from Alan Rhoda.  He wrote:

You here express the tense-logical idea that p –>FPp, that if something is the case, then it will thereafter always be the case that it has been the case. In Latin, facta infecta fieri non possunt. [The done cannot be undone.]

Believe it not, this has been denied by the famous Polish logician Lukasiewicz, no less. He seems to have accepted a version of presentism according to which (1) all (contingent) truths depend for their truth on what presently exists, and (2) what presently exists need not include anything that suffices to pick out a unique prior sequence of events as "the" actual past. Accordingly, truths about the past may cease to be true as the passage of time obliterates the traces of past events. Lukasiewicz apparently found this a comforting thought:

"There are hard moments of suffering and still harder ones of guilt in everyone’s life. We should be glad to be able to erase them not only from our memory but also from existence. We may believe that when all the effects of those fateful moments are exhausted, even should that happen only after our death, then their causes too will be effaced from the world of actuality and pass into the realm of possibility. Time calms our cares and brings us forgiveness." (Jan Lukasiewicz, "On Determinism" in  Selected Works, ed. L. Borkowski, North-Holland, Amsterdam, 1970, p.128.)

Lukasiewicz JanThat is  to my mind an amazing passage from Lukasiewicz both because of his rejection of the tense-logical principle, p –>FPp,  and because of the consolation he derives from its rejection.

I myself find it very hard to believe that there wasn't an actual unique past. I find it impossible to believe that, with the passage of enough time, past events will somehow go from being actual to being merely possible. It seems obvious to me, a plain datum, that there is an important difference between a past event such as Kierkegaard's engagement to Regine Olsen, which actually occurred, and a merely possible (past) event such as his marriage to her which did not occur, but could have  occurred, where 'could have' is to be taken ontically and not epistemically. Now that datum tells against presentism — unless you bring God into the picture which is what Rhoda does.  For if the present alone exists, then the wholly past does not exist, which implies that there is no difference between a merely possible past event and an actual past event.

Alan Rhoda responds:

Yes, in my paper "Presentism, Truthmakers, and God" (Pacific Philosophical Quarterly 2009). I argue that the best way for presentists to supply truthmakers for truths about the past is to appeal to divine memories.

I accept the datanic nature of your distinction between the actual and the merely possible past. I'm not clear, however, on why that distinction by itself should count against presentism. Unlike Lukasiewicz, most presentists do posit present grounds for that distinction. The live question is what sort of present facts, if any, could serve the presentist's purposes. That's where my argument for theistic presentism gets its purchase.

If only that which exists now, exists, then that which existed does not exist. If to exist = to be actual, then that which existed is not actual. Since what existed is presumably not impossible, that which existed is merely possible. It therefore looks as if one can get very quickly from the distinction I pointed out to a rejection of atheistic presentism. Atheistic presentism cannot supply the truth-makers for past-tensed truths such as 'Kierkegaard was engaged to Regine Olsen.'

Atheistic presentists need to find present facts to ground the distinction in question.  Now there are some present facts that could serve to ground some past-tensed truths. Consider 'Bill Sykes the burglar entered my house yesterday.' This contingent truth needs a truth-maker, and on presentism this truth-maker must exist today. Our presentist might plausibly say that it is Sykes' footprints outside my window, and the the broken glass, both of which exist today, that tie Sykes to the crime and make-true the contingent sentence in question.  But what makes it true that my grandfather Alphonso drank a glass of dago red on New Year's Day, 1940 and pronounced it excellent?  Suppose the red wine drunk by Alphonso came from the Gallo vineyard. What now makes it true that that particular glass of dago red came from the Gallo vineyard as opposed to the Cribari vineyard? What exists now that could serve as a truth-maker of such truths?  There are plenty of past-tensed truths that have no presently existing truth-makers.  This is why Rhoda argues that it is only present facts involving divine memories that are up to the truth-making job.

Whether recourse to God and his omniscience works to save presentism we leave for later. 

How to Write a Good Comment

I offer a comment of mine as an example.  It is a brief response to a Substack entry by Elliot Crozat.  Here is the comment:

Very nice post, Elliot. Your reconstruction is valid. You say that (2) is "solid." It is, but it is not self-evident. For one epistemically possible view is that the dead are nonexistent objects: they do not exist, but they have being, and have properties. Indeed, they actually have properties; it is not just that they could have properties. So on this view, there is no bar to a dead person's having the property of being communal or standing in the communal relation to other dead persons. This quasi-Meinongian view is skillfully developed by Palle Yourgrau in Death and Nonexistence (Oxford, 2019). It of course has problems of its own.

(5) and (7) are undoubtedly true.

And I agree with you that (1) is reasonably rejected on eternalism which is a plausible alternative to presentism. Surely wholly past individuals are not nothing despite their not being temporally present. They exist, but not at present. Presentists, despite a lot of fancy footwork, have a hard time accounting for this plain fact. This is one reason why eternalism is well-represented among contemporary philosophers. Eternalism allows for a watered-down personal immortality which has been embraced by Einstein, Charles Hartshorne, and most recently by John Leslie. The main difficulty of eternalism is to give a clear account of existence simpliciter. But it appears that the presentist faces the same difficulty assuming that "Only the present exists" is not a miserable tautology that boils down to "Only what exists (present tense) exists (present tense."

As for Aristotle, he is standardly taken to be a presentist (see Feser, e.g.) and thus your invocation of the Stagirite in support of eternalism is questionable.

PROVISIONAL PHILOSOPHICAL REFLECTIONS
 
Time, Death, and Existence
 
Cormac McCarthy’s The Sunset Limited contains many good lines. Here’s one from near the end of the play: “You can’t be one of the dead because what has no existence can have no community.” As I take it, “one of the dead” means “one belonging to a community of dead persons.”
 
 
JUNE 27, 2023
 
……………………….
 
So what makes my comment good?
 
1. I interact directly with what the  author has written.
2. In doing so, I show that I have made a good faith attempt to understand him.
3. I tell him whether I agree or disagree and why.
4. I do not go off on irrelevant tangents.
5. I keep my comments brief and to the point.
6. I try to be helpful.
7. I do not use his site to promote myself or to advertise my wares or to dump large undigested quotations from other writers.

A Mistake of Memory

One mistake we sometimes make is to confuse a memory of a decision to do something with a memory of having done it. "I thought I did that! No, my man, you merely thought of doing it." 

One morning I wasted time searching for an article I had printed out the day before. But I was searching for a nonexistent object. I hadn't printed it out; I had merely resolved to do so. I confused resolve with result.

Memory, then, is fallible. But it is via memory that we know this. The non-veridical memory of having printed the document is known to be non-veridical by comparison with the veridical memory of having intended to print it. So while fallible, memory is a source of knowledge, and generally reliable, although its powers vary from person to person. 

Veridical memory  of wholly past events gives the lie to presentism, the view that the present alone exists. For if the present alone exists, then the wholly past does not exist. But what does not exist cannot be known. Given that some memories are veridical, presentism is false. 

"So what are you saying, man? That the past is real?"

False Memory

Yesterday I intended to print a document, loaded the paper tray, and then got sidetracked by a phone call.  I forgot about the print job. This morning I falsely remembered having printed the document and then wasted time searching for it. 

What philosophical juice might one squeeze from this lemon?

1) Not all memories could be false. If all memories were false, then one could not know, using memory, that some memories are false. But I do know, by memory, the truth that some memories are false. Therefore, it is not possible that all memories be false. 

2) If presentism is the view that only temporally present events exist, and that wholly past and wholly future events do not exist, then the above example shows that presentism thus defined cannot be true. For I now veridically remember yesterday's intention to print the document, yesterday's loading of the tray, and yesterday's phone call. These events occurred, and I now know they occurred; hence they cannot now be nothing.

Existence, Time, Property-Possession, and the Dead

Here are four propositions that are individually plausible but collectively inconsistent. 

1) For any x, temporal or atemporal, if x has a property, then x exists.

2) For any temporal x, if x exists, then x exists at present.

3) Frege, a temporal item, does not exist at present.

4) Frege has properties at present.

(1) is plausible: how could anything have a property if it is not 'there' to have it? This use of 'there' is non-locative.  I assume that to exist = to be, and that Meinongian nonentities, "beyond being and nonbeing," are unintelligible.

(2) is plausible: the past is no longer, the future not yet; the present alone is real/existent!  It is important to note, however, that the plausibility of (2) is not that of a tautology. Tautologies are plausible in excelsis; substantive metaphysical claims are not. One cannot reasonably controvert a tautology; one can reasonably controvert a substantive metaphysical claim. What (2) formulates, call it 'presentism,' is somewhat plausible but surely not logically true. So the senses of 'exist(s)' and 'exist(s) at present' are distinct. If I say that a thing exists, I say nothing about when it exists; I say only that it is 'there' in the non-locative sense among the 'furniture of the world.' Indeed, 'x exists' leaves open whether the thing is in time at all. 'God exists' is noncommittal on the question whether God is temporal or atemporal. 

(3) is plausible: (a) Frege is temporal in that he cannot exist without existing in time; (b) Frege does not now exist.

(4) is plausible: Frege is now famous and he is dead. Those predicates are true of him: he has (instantiates) the properties they express. 

The tetrad is collectively inconsistent. One way to solve the problem is by rejecting the least plausible proposition. By my lights, that proposition is (2). To reject (2) is to reject presentism. But if presentism is false, it does not follow that eternalism is true!  

Memory and Existence: An Aporetic Tetrad

Try this  foursome on for size:

1) Memory is a source of knowledge.

2) Whatever is known, exists.

3) Memory includes memory of wholly past individuals and events.

4) Whatever exists, is temporally present.

The limbs of the tetrad are collectively inconsistent: they cannot all be true.  To appreciate the logical inconsistency, note that 'exists' in (2) and in (4) have exactly the same sense, and that this is not the present-tensed sense.  It is the tense-neutral and time-independent sense. Something that exists in this sense simply exists: it is one of the things listed in the ontological inventory.  Hence talk in the literature of existence simpliciter.  In both of its occurrences above, 'exists' means: existence simpliciter.

The limbs are individually plausible. But they are not equally plausible. (4) is the least plausible, and thus the most rejectable, i.e., the most rejection-worthy. Rejecting it, we arrive at an argument against presentism given that (4) is a version of presentism, which it is.

1*) Some of what is remembered is known.

2*) All that is known, exists.

Therefore

2.5) Some of what is remembered exists.

3*) All of what is remembered is wholly past.

Therefore

3.5) Some of what exists is wholly past.

Therefore 

~4*) It is not the case that whatever exists, is temporally present. (Presentism is false.)