Abstract
My analysis of temporal direction begins by establishing that time-reversal scenarios, scenarios in which the direction of time itself is reversed, whether locally or globally, are incoherent. Building on this conclusion, I argue that temporal directionality cannot be defined or explicated in terms of processes in time, such as the movements of celestial bodies, biological evolution or radioactive decay. In other words, while it is easy to imagine any process occurring in reverse, one cannot define the "earlier"/"later" relation by appeal to the stages of a process, for example, the consecutive stages of radioactive decay. The second section of the paper turns to a study of our firsthand experiences, and qualifies this result by arguing that experiences constitute the one class of events that cannot so much as be conceived as reversed in time. In the third section I suggested that our firsthand experiences figure as a standard by means of which temporal direction is given to us. I further argue that, despite the pivotal role played by experience in this scheme, we are fully warranted in being realists with respect to temporal directionality.
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Notes
Supposedly, according to physics, “whatever can happen, can also happen backwards in time” (Earman 2002). I discuss and reject this thesis in ….
Richard Feynman, “The Theory of Positrons,” Physical Review 76, Issue 6 (1949): 749–59.
Mellor, Real Time II, 120–1 (1998).
Disturbingly, talk of “the past hypothesis” sometimes leads to conjectures that in a world subject to a “future hypothesis” we would remember the future and anticipate the past. So, like in the above scenario, we’d remember our 80th birthday, just that now it would be future rather than past. However, for reasons that cannot be elaborated here, I am convinced that notions such as “remembering the future” are meaningless.
Tim Maudlin, “On the Passing of Time”, in The Metaphysics within Physics (Oxford University Press, 2010), Ch. 6, pp. 104–142, on pp. 123–4.
Ibid, 124.
Williams, D.C., “The Myth of Passage”, Journal of Philosophy, vol. 48 (1951): 457–471. This argument was later endorsed by Huw Price in his Time’s Arrow and Archimedes’ Point: New Directions for the Physics of Time (2011), (New York and Oxford: Oxford University Press, 1996). See also Price’s “The Flow of Time”, in Callender, C. (ed.), The Oxford Handbook of Philosophy of Time. For a concise version of this argument see Kristie Miller, “Time Passages”, Journal of Consciousness Studies, 24, No. 3–4 (2017): 149–76, on p. 155.
Previously I claimed reversed processes can be readily imagined, while time reversal cannot. That of course does not mean that the reversal of every process yields something recognizable. An omelet can be imagined becoming an egg, but when the dynamics inside a computer’s CPU, or inside a brain, is reversed, the result is not something we have a name for. Obviously, just calling it “computation” or “experience” will not turn it into one.
By “majority” here I mean the many thinkers who identify themselves as eternalists (or B-theorists – in this context the distinction is not important). I find the widespread resistance to the claim that relations of succession are merely psychological curious, not because I think it is tenable, but because of the ease with which passage is thrown, by the same thinkers, into the bin of the “merely psychological”, Cf., my “----”.
Since the topic of this paper is time, a host of important philosophical issues pertaining to the nature of experience (such as the relationship between experience and dreams and hallucinations, the internalism/externalism debate, and others) will be ignored here.
I am grateful for the forceful criticisms of an anonymous referee that led to this formulation of the argument.
Obviously speaking of pointlike states is a distortion, we need to speak of processes that extend in time, of ice melting, or accumulating. But the distortion simplifies the discussion without, so far as I can tell, undermining the argument.
I reject this understanding of the 2nd law, but that is not our topic (discussed in my …)
One objection that comes up in this context stems from the fact that the meter rod can be measured, e.g., by the “inches rod”. I have responded to such objections previously, and, at any rate, they are irrelevant to the current discussion.
This possibility leads Kripke to his, I believe, invalid criticism of Wittgenstein on this issue in Naming and Necessity (Harvard University Press, 1980), pp. 54–5. (Wittgenstein’s remarks are in §50 of his Philosophical Investigations). For a more elaborate discussion see my …
In this context the notion of “a convention” occasions much confusion, because it leads into the false supposition that we have a grip on magnitudes independently of standards, that standards only allow us to express what we already apprehend before we have them, whereas in reality our understanding of a magnitude is inextricable from our understanding of how to use of the standard with which it is measured. Even for a child, the notion of length is given via a comparison, that is, via a provisional standard.
It is worth noting that the latitude in the spatial case is not unlimited - not every object can figure as a standard for length, most cannot. Conversely, latitude is not entirely absent from the temporal case - the standards that ground direction are selected from an albeit restricted pool of present, first-hand experiences.
References
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Feynman, R. (1949). The theory of positrons. Physical Review, 76(Issue 6), 749–759.
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Maudlin, T. (2010). “On the Passing of Time”, in The Metaphysics within Physics (Oxford University Press), Ch. 6, pp. 104–142, on pp. 123–4.
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Williams, D. C. (1951). The myth of passage. Journal of Philosophy, 48, 457–471.
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Dolev, Y. “On the essence of temporal directionality and its irreversibility”. Phenom Cogn Sci 18, 589–601 (2019). https://doi.org/10.1007/s11097-018-9586-7
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DOI: https://doi.org/10.1007/s11097-018-9586-7