Something I find puzzling is that many people in intellectual circles seem to embrace the so-called eternalist view of time, which holds that the past, present, and future all equally exist already, yet at the same time, in terms of practical ethics, these same people focus exclusively on impacting the future. These two positions do not seem compatible, and it is interesting that no one seems to take note of this, and that no attempt seems to be made at reconciling them, or otherwise examining this issue.
For why, given an eternalist view of time, should one focus on impacting the future rather than the past? After all, the eternalist view of time amounts precisely to the rejection of the common sense view that the past is fixed while the future is not, which is the common sense view of time that seems to underpin our common sense focus on trying to impact the future rather than the past. So how can one reject the common sense view of time that seems to underlie our common sense practical focus, yet then still maintain this focus? If the past and the future equally exist already, why focus more on trying to impact one rather than the other?
The only attempted reply I have heard to this question so far, which came from Brian Tomasik, is that if, hypothetically, the present were different, then the future would be different, and hence it makes sense to focus on such changes that would render the future different. The problem, however, is that the same argument applies to the past: if, hypothetically, the present were different, then, for the equations of physics to be consistent, the past would also have to be different. Tomasik seemed to agree with this point. So I fail to see how this is an argument for focusing on impacting the future rather than the past given an eternalist view of time.
There are various ways to respond to this conundrum. One can, for instance, try to argue that there is no conflict between eternalism and focusing only on impacting the future (which seems the prevailing assumption, but I have yet to see it defended). Another path one could take is to argue that we in fact should focus on impacting the past just as much as the future (something I find highly dubious). Alternatively, one could argue that it is just as senseless to try to change the future as it is to change the past (something few would be willing to accept in practice). Lastly, one could take the tension between these two widely esteemed views to imply that there may be something wrong with the eternalist view of time, and at the very least that we should lower our credence in eternalism, given its ostensible incompatibility with other, seemingly reasonable beliefs.
My Preferred Path: Questioning Eternalism
I would be curious to see attempts along any of the four paths mentioned above. I myself happen to lean toward the last one. I think many people display overconfidence with respect to the truth of eternalism. The fact that the equations of the theory of relativity, as they stand, do not demand an ontologically existing “now“ does not imply that no such thing exists (where this now, it must be noted, is not defined by “clocks all show the same”, as such a now clearly is impossible; yet there is no contradiction whatsoever in the existence of a unique, ontologically real “present” in which initially synchronized clocks show different times). In other words, although the equations of relativity do not demand the existence of such a now, they do not rule it out either. Yet it seems a widely entertained fallacy that they do, and people thus seem to accept that eternalist view as though it were a matter of logical certainty, when it is not. I think this is bad philosophy. And I think it is important to point this out, since false certainties can be dangerous in unexpected ways (for example, if the above-mentioned fallacy led us to falsely conclude that trying to impact the future is senseless).
Beyond that, as I have noted elsewhere, one can also question to what extent it makes sense to say — as eternalists often do, and as the name eternalism itself implies — that all moments exist “always”? After all, doesn’t “always” refer to something occurring over time? The meaning of claims of the sort that “every moment exists always” is, I believe, less obvious than proponents of eternalism appear to think, and seems in need of unpacking.
A General Note on Our Worldview
I think the tension explored here speaks to a more general point about our worldview, namely that we often do not derive the more practical views we hold (such as the view that we can influence the future but not the past), from our fundamental ontological theories of how the world works. Instead, such views are often derived mostly from tacit common sense notions and intuitions (which is not to say that these views should necessarily be rejected, and certainly not on this ground alone). This means that sometimes — quite often, in fact — the views we hold on various subjects, such as the philosophy of time and practical ethics, are scarcely compatible. The project of bringing the various beliefs we hold across these different areas in concert is, I believe, an important and potentially fruitful one, for our theoretical views in themselves, as well as for our pratical efforts to act reasonably in the world.