C‐theories of time: On the adirectionality of time

Abstract

The universe is expanding, not contracting. " Many statements of this form appear unambiguously true; after all, the discovery of the universe's expansion is one of the great triumphs of empirical science. However, the statement is time-directed: the universe expands towards what we call the future; it contracts towards the past. If we deny that time has a direction, should we also deny that the universe is really expanding? This article draws together and discusses what I call 'C-theories' of time-in short, philosophical positions that hold time lacks a direction-from different areas of the literature. I set out the various motivations, aims, and problems for C-theories, and outline different versions of antirealism about the direction of time.

What’s so Special About Initial Conditions? Understanding the Past Hypothesis in Directionless Time

“…Table 1: A-theories, B-theories and C-theories understood in terms of a descending hierarchy of structure attributed to time, from Farr (2020).…”

“…Rejecting P2 involves putting forward a different understanding of the C-theory. Such a version is motivated by remarks made by Reichenbach (1956), which I elsewhere (Farr, 2020(Farr, , 2021 term time direction conventionalism, according to which there are no time-directed facts, but it is more convenient to describe the world from past to future. Central to the Reichenbachian account is the idea that although past-to-future and future-to-past descriptions of the world are equivalent, it does not follow that it is as true to say that the Past State is a product of entropy-decreasing behaviour as it is to say that the present state is the product of entropy-increasing behaviour.…”

Conventionalism about time direction

“…First, I show how conventionalism is an antirealist account of time direction 26 that manages to maintain some key motivations of realist accounts, making it a best-of-both-worlds view. And second, I argue that conventionalism helps to clarify24 SeeFarr (2022a) for an extended discussion of the question and critique of Reichenbach's remarks about the direction of psychological time.25 Of course, Reichenbach's conventionalism about geometry has its origins in Kantian epistemology, and in this sense one can speculate as to whether Reichenbach held analogous views about Euclidean geometry being simpler, more natural, or more convenient for us in part due to facts about our spatial psychology, in line with Kant.26 In terminology I defend elsewhere(Farr 2020), conventionalism is a C-theory of time insofar as it holds that there is a key sense in which time is adirectional-crucially there are no time-directed facts according to conventionalism, and so time ultimately lacks a direction in that specific sense.…”

Can Sinners Really Change? Understanding Personal Salvation in the Block Universe

“…It has not featured prominently in the literature due to its highly counter‐intuitive denial of time's directionality. Nevertheless, interest in this view is growing, and one can turn to Matt Farr for an exposition and defense of it (Farr, 2020). As the C‐theory is also committed to a block universe metaphysic, its implications for the doctrine of salvation are largely the same as those identified in this article and a parallel analysis of salvation given a C‐theory is not necessary.…”