In our Study of the Day feature series, we highlight a research publication related to a John Templeton Foundation-supported project, connecting the fascinating and unique research we fund to important conversations happening around the world.
For Albert Einstein’s 70th birthday, his friend and walking companion Kurt Gödel gave the physicist an unusual gift: an exacting mathematical proof, rooted in Einstein’s own theory of relativity, that time could not exist (Gödel’s wife had knitted Einstein a birthday sweater, but decided not to give it). Gödel’s offering was a 20th-century variant of a metaphysical conclusion that certain philosophers have reached before: one of the most intuitively obvious aspects of our lived experience, time itself, might be a logical impossibility.
The ancient Greeks had their versions of that argument, as did a host of great Buddhist philosophers including Nāgārjuna, writing in third-century India, the 13th-century Zen poet Dōgen, and the 14th-century Tibetan scholar-yogi Longchenpa. In Western philosophy, Immanuel Kant touched on the issue, and in 1908 J.M.E. McTaggart laid his cards on the table with The Unreality of Time. Since then, numerous philosophers, logicians and physicists (including Julien Barbour, who wrote The End of Time and Carlo Rovelli, who has found Nāgārjuna’s philosophy helpful for his own timeless grappling with quantum gravity).
“It seems unlikely,” writes Kristie Miller, co-director of the Centre for Time at the University of Sydney, “that when McTaggart, Gödel, Barbour (et al) and Dzogchen practitioners say that there is no time, they are denying the existence of the same thing.”
What does it take for there to be time?
To help make sense of the landscape of time and non-time, Miller wrote “A Taxonomy of Views about Time in Buddhist and Western Philosophy,” a book chapter that patiently disentangles and clarifies which philosophers have argued what sorts of time do or don’t exist.
Miller begins with what she considers the most ‘hard-nosed’ and exacting set of possible requirements. The hard-nosed approach says that for time to exist it needs to flow asymmetrically (moving forward and moving backwards in time must be fundamentally different), and it needs to be describable in terms of objective past, present and future that can’t be reduced to a series of relational statements (that one thing happened before, or during, or after another thing).
Not every philosopher of time holds that all of those features are necessary for time to exist: Miller groups many in ‘middle-way’ approaches, which say that while time must have an asymmetric flow in which causes always or nearly always precede their effects, it’s alright if you can only describe its progression relationally.
Finally, there are what Miller terms ‘undemanding’ definitions of time, which hold that time only requires relational description. (Even at this low bar, some philosophers still argue that there can’t be time.)
For Miller, philosophers committed to each level of requirement can then be termed “realists” (who say that time as observed is capable of meeting that set of requirements or “error theorists” who say it falls short. What you end up with is a six-category matrix in which you can attempt to place various philosophies of time. She cites examples of Buddhist and Western thinkers whose ideas land in each category.
In Miller’s taxonomy, Gödel is a hard-nosed error theorist, saying that time would have to be objective and asymmetric (but it isn’t). Longchenpa, who distinguishes four flavors of time (ceased, not-lingering, not-yet-coming and timeless) is a hard-nosed realist, for whom time can logically exist.
As a testament to the breadth and subtlety of his work, Nāgārjuna is hard to pin down: one school of interpretation sees him rejecting hard-nosed conceptions of time without endorsing anything else. From another vantage point, he would seem to be an undemanding error theorist, saying that all proposals for the nature of time depend on there being ultimate truths — which don’t exist. Still, much of his work seems to allow for the fruitfulness of discussing things which are conventionally, but not ultimately true. In that view, Nāgārjuna is “someone who thinks there are no truths, properly speaking, but that we can and should continue to engage in our current discourses and retain our current practices.”
Time may indeed be an illusion, but you still shouldn’t show up late to the party.
Read more an American Philosophical Association interview with Kristie Miller on her work on the philosophy of time.