Conference coordinated by Alexandre Declos.
→
Symposium
The metaphysics of time : contemporary perspectives
→
from
to
See also:
Time has always fascinated philosophers. The intimate consciousness, perception and experience we have of it, as well as the phenomenological description we can give of it. The 20th century saw a renewed interest in the more directly metaphysical aspects of time. Philosophers increasingly focused on the ultimate nature of time, its reality and objective properties. How can we be so sure of the reality of time? Why think that temporal order is more than just an appearance? Is there, as some people (the "A-theorists") think, a real movement of things and events through the temporal dimension, in which case time would consist of a series whose members would be endowed with dynamic and transitory "A-properties", that of being successively future, present and then past? Or, as others (the "B-theorists") think, does time ultimately boil down to a series in which things and events maintain simple relations of anteriority, simultaneity and posteriority, in which case time would be reducible to a system of fixed, immutable relations ("B-relations")? Or should we say that there are no A-properties and, more generally, that time doesn't pass?
Another contentious issue concerns the ontological status of the past, present and future, and more specifically of their respective occupants. Thus, for a "presentist", the past is no more and the future is not yet: only the occupants of the present moment, which never stops changing, really exist. Conversely, for an "eternalist", past, present and future all exist in the same way. Just as Moscow really exists without being here in Paris, the Battle of Waterloo and the extinction of the Sun exist just as much, even if these events are not taking place now, in 2019. For the eternalist, the universe forms a "block" where all temporal dimensions are ontologically equal, without any privileging of the present. A third option envisages a "growing universe", where only the past and present truly exist. Every new moment would be added to the total inventory of being, which would continue to grow. These are all invitations to the metaphysician to clarify the ontological status of entities that are not present.
Another lively topic of discussion concerns the persistence of objects over time: how can numerically identical things exist at different times? For the common-sense proponents of "endurantism", material objects persist by being "fully present" at every instant of their existence. Reality is made up of three-dimensional entities, fully contained in the space they occupy at each moment in time. For "perdurantists", on the other hand, material objects are extended in space and time. In addition to their spatial parts, they also have "temporal parts" by virtue of which they persist: we would therefore never see "whole" objects, but rather temporal parts or "slices" of more extended objects or "four-dimensional worms". Despite the theoretical benefits of perdurantism, can we nevertheless live with such a revision of common sense and so readily admit the existence of temporal parts?
In addition to these questions, which are among the most topical today, the colloquium will also provide an opportunity to revisit the most classic themes in the metaphysics of time. These include: What is the ultimate nature of time? Does it consist solely of the present moment, or do past and future also exist? Can we change the past? Can there be a world without time? What is the relationship between time and change? Does time pass even if nothing changes? Can we even say that time "passes"? How do objects persist within it? Are ordinary and scientific images irreconcilable? How can we understand the relationship between time and space, and the analogy we sometimes draw between space and time, particularly in science? Must we accept the idea that the future is "open" and the past "closed"? Is there a direction to time? Is time travel possible?