Practical metaphysics: presentism vs eternalism

How the metaphysics of time affects your thoughts and actions in the present

Contemplating eternity, by Midjourney.

Generally speaking, I’m pretty skeptical of metaphysical speculations, because too often they are detached from actual empirical evidence (i.e., science). Then again, I also think that there are connections between how we understanding the world (metaphysics in the broad sense, including science) and how best to act in the world (ethics).

Which is why I was intrigued by a paper published by Mauro Dorato, of the Third University of Rome, in the journal Argumenta (2021:1-19). In it, Dorato compares two fundamental theories in the metaphysics of time, presentism and eternalism, and investigates their implications for ethical behavior, with particular attention to the Epicurean notion of living in the present, or seize the day (carpe diem) and the Stoic and Spinozean idea of looking at one’s life from the point of view of eternity (sub specie aeternitatis).

Dorato’s project is to argue that presentism and eternalism, far from being merely speculative notions in metaphysics, actually affect the behavior and emotional responses of people who accept either position. But do believers in metaphysical presentism and eternalism actually feel and act in accordance with their adopted accounts of time? Should they?

First off, let’s get clear on what the two metaphysical positions actually are. Presentism holds that only the present moment is real. According to this view, past events have ceased to exist and future events don’t yet exist—there’s just the ever-changing “now” that constitutes reality. Think of it like a spotlight moving through time, where only what’s illuminated (the present) actually exists. This is also the common sense view of how time works.

By contrast, eternalism (also called the “block universe” theory, in modern parlance) argues that past, present, and future all exist equally. From this perspective, time is more like space—just as distant places exist even though you’re not there, distant times exist even though you’re not “when” they are. Your birth, this moment, and your future death are all equally real parts of a four-dimensional spacetime block. If you want a sense of how this would work, check out Kurt Vonnegut’s novel, Slaughterhouse Five, and get acquainted with the fascinating alien species known as the Tralfamadorians.

The key contrast between the two accounts concerns what’s ultimately real: presentists say only “now” exists, while eternalists say all times exist. This leads to different views on temporal flow—presentists see time as genuinely dynamic (things coming into and going out of existence), while eternalists see our sense of temporal passage as a subjective illusion arising from our perspective within the block.

Presentism aligns better with our intuitive experience of time, but eternalism finds support in Einstein’s relativity theory, which suggests there’s no universal “now”—simultaneity is relative to reference frames. Then again, as Dorato puts it, “the eternalist has to explain why we seem to find ourselves in different regions of spacetime in a purely relational way, as well as the fact that we first anticipate the same event, then we experience it and then we remember it.” (p. 4) Just talking about “illusions” isn’t going to cut it, unless one has a precise account of how and why such illusions arise.

You can also think of presentism as looking at time from a personal, local perspective, and eternalism as adopting a god’s eye view of things, in which case the underlying reality, whatever we mean by “time,” would be the same, but it would translate differently depending on the point of view of the observer.

Now, both presentists and eternalists are aware of the limited duration of a human life, and in both cases it is such awareness that motivates a focus on the here and now, with as little emotional energy spent on regretting the past or worrying about the future. (Notice that this doesn’t mean that one shouldn’t learn from the past and prepare for the future, the difference being that regret and worry are emotional states, while learning and planning are analytical attitudes.)

A classic example of practical presentism from the Hellenistic tradition is the letter by Epicurus to his friend Menoeceus, where he famously writes:

“Foolish, therefore, is the man who says that he fears death, not because it will pain when it comes, but because it pains in the prospect. Whatever causes no annoyance when it is present, causes only a groundless pain in the expectation. Death, therefore, the most awful of evils, is nothing to us, seeing that, when we are, death has not come, and, when death has occurred, we are not.”

The idea is that, from a rational perspective, we should suffer only for things in the present, because past and presents are only ghosts that exist in either memory or expectation. Moreover, for a presentist, there can be happiness only in the here and now because past and future literally do not exist.

Dorato correctly notes that Epicurus’s argument starts with the metaphysics of presentism, from which he derives the conclusion that we and death cannot possibly “be” at the same time, from which it further follows that it is not rational for me to be fearful of death now, since it is not here (yet). The sequence, then, is: metaphysics > ontology > belief > affective reaction.

By contrast, the eternalist recommendation is to engage in exercises of self-transcendence of time, training ourselves to treat the present, past, and future in the same guise, because that reflects the true reality of the cosmos.

In his paper, Donato distinguishes three versions of eternalism, which I will briefly discuss: the Stoic one, Spinoza’s, and Bertrand Russell’s.

It isn’t clear to me that the Stoics were eternalists in the modern sense of the term, but they did adopt a metaphysics of eternal recurrence of events, and certainly advocated an the cultivation of time transcendence, because we are best placed to put the present in the proper perspective when we zoom out, so to speak, and contemplate the vastness of time before and after the current moment. The idea is that such contemplation helps us to accept whatever the universe is throwing our way right now. As Marcus Aurelius puts it:

“You have the power to strip off many superfluous things that are obstacles to you, and that depends entirely upon your value-judgements; you will open up for yourself a vast space by embracing the whole universe in your thoughts, by considering unending eternity, and by reflecting on the rapid changes of each particular thing; think of how short is the span between birth and dissolution, and how vast the chasm of time before your birth, and how the span after your dissolution will likewise be infinite.” (In Hadot 1995:183)

In his Ethics, Spinoza adopts a metaphysics very similar to that of the Stoics, featuring eternal, deterministic laws of nature and the absence of Aristotelian teleology (and, hence, of purpose). Spinoza distinguishes between what he calls “imagination” and reason. The former is the tool that leads us to mistakenly distinguish between present, past, and future; it focuses on the contingent, and cannot grasp the universal laws themselves. But reason can:

“It is in the nature of reason to perceive things under a certain form of eternity (sub quâdam æternitatis specie).”

Spinoza goes on to identify the universal laws grasped by reason with an immanent god, deus sive natura, that is, literally, “god or nature,” just as the Stoics thought. When, through reason, we understand all this, according to Spinoza, we achieve the highest possible form of knowledge, what he calls the intellectual love of god. Accepting that the universe is deterministic, then, not only doesn’t cause despair or resignation, but yields joy at the realization that we are one with god / nature.

The third eternalist philosophy that Donato discusses is that of Bertrand Russell, as articulated in his Mysticism and Logic. Here is how Bertie himself puts it:

“The felt difference of quality between past and future, therefore, is not an intrinsic difference, but only a difference in relation to us: to impartial contemplation, it ceases to exist. And impartiality of contemplation is, in the intellectual sphere, that very same virtue of disinterestedness which, in the sphere of action, appears as justice and unselfishness. Whoever wishes to see the world truly, to rise in thought above the tyranny of practical desires, must learn to overcome the difference of attitude towards past and future, and to survey the whole stream of time in one comprehensive vision.” (1917, 22)

Despite being a critic of the Stoics, Russell here is putting forth the very same exercise that Marcus Aurelius recommends: train yourself to think more objectively about the vastness of time and this will translate in increased equanimity in the way you deal with the here and now.

Donato, of course, points out that it is difficult for the presentist not to be occasionally reminded of the past or have his thoughts orient themselves toward the future, just as it is difficult for the eternalist to always abstract from the here and now and contemplate the full span of time. Nevertheless, the two philosophies recommend different attitudes and actions: the presentist will train his attention to gently return to the here and now, while the eternalist will train his mind to look at things, as much as possible, sub specie aeternitatis.

There are specific activities that may help cultivate either metaphysical perspective. For instance, aesthetic contemplation, conversation, play, and scientific research are all activities during which we tend to focus on the present, with little intrusion from either the past or the future. By contrast, studying history or the historical sciences (astronomy, evolutionary biology, geology, paleontology) may be a good way to get into the eternalist mode.

Whether you are a presentist or an eternalist, it will be challenging, but not impossible, to align your feelings with your metaphysics. Einstein himself appreciated the problem when he wrote, on May 21, 1930, a letter of condolence to the mathematician Elie Cartan, in which he said:

“In these trying moments one feels how it is difficult for a human being to hold fast to the idea—so inescapable to a physicist—that the now is only an illusion, not something pertaining to reality.”