The year 1905 was a special one for the subject of time: the Annalen der Physik published Einstein’s article establishing the theory of special relativity, and Husserl gave his lecture course at the University of Göttingen, which Heidegger published in 1928 as Vorlesungen zur Phänomenologie des inneren Zeitbewußtseins [The Phenomenology of Internal Time-Consciousness]. On the one hand, this was the time of modern physics, where the distinction between present, past and future made no sense; on the other, it was the time of consciousness, or “temporality,” centered on the living present in its state of tension with the remembered past and the anticipated future. These two radically distinct approaches to the problem of time ignored each other and continued to diverge throughout the twentieth century.
The main strength of Francis Wolff’s book is that it proposes a third way, one that takes into account both physical and phenomenological approaches, while exploring new avenues. Inspired by Strawson’s descriptive metaphysics, which “draws out the ontology that underlies our ordinary discourse” (p. 29), his method combines conceptual analysis and, following on from his book Dire le monde (1997), a reflection on the “language-world,” i.e. the world as constituted by and in proportion to language. What is time as it is said and thought in this world of ours? While physics adopts the “point of view of nowhere” and phenomenology takes the first-person perspective, Wolff’s approach analyzes the world and time from the point of view of the “linguistic we”. The aim is not simply to question the uses of the temporal notions that permeate ordinary language (“before,” “after,” “during,” “at the same time,” etc.) and to study how to say time—which brings us back to the phenomenological approach [1]—but to take as its more general subject “world time” in both its subjective and objective aspects: “The descriptive metaphysics of time seeks to analyze the concept of time. Its subject is world time. This is time as it exists both outside us (in contrast to subjective time as it appears to a consciousness, the object of phenomenology) and for us (as opposed to the time of nature, addressed by the theories of the physical sciences)” (p. 42). The focus of Wolff’s study is therefore world time, or more precisely its concept, since the author emphasizes, in opposition to Kant, that time is a concept, not an intuition.
Persistence, succession, and simultaneity
Once Wolff has established his methodological framework, he leads the reader on a detailed and fascinating investigation, written in a language that marries the technicality of the argument with a clear presentation. His purpose is to explore the concept of time in all its essential features (uniqueness, continuity, density, infinity, irreversibility, succession, etc.) and related notions (change, existence, causality as the basis of temporal asymmetry, etc.), while tackling one by one the classic aporias that reopen the questioning in each chapter. The first of these, which can be traced back to antiquity, is whether time exists by itself or only in relation to other entities (events, consciousness). Wolff decides in favor of a realist position—“Time exists by itself and does not depend on thought”—and a substantialist one—“Time exists by itself and does not depend on events” (p. 58). Not only should we not confuse time with the dynamics of events, but we should also endeavor to conceive of it in abstraction from the events that unfold within it.
Another core question that runs throughout the book is whether time is definable, or whether it is a primitive concept, in which case any attempt at definition is doomed to circularity. Whether we define it, for example, as “order of succession” (Leibniz) or “number of movements according to the anterior-posterior relation” (Aristotle), we call upon notions that seem to imply time—such as succession, when it is distinguished from logical or spatial order—or movement, which cannot be thought of without space and time. When it comes to the problem of the relationship between time and change, Wolff’s view goes against the mainstream, basing his theory on the link between time and persistence.
Aristotle is widely credited with the idea that there is no time without change, since change is its sum or measure: the sleepers of Sardinia awaken thinking that no time has passed, because in their sleep they have not perceived any change [2]. And yet, as Wolff observes, time is the measure of movement and rest for Aristotle, so if there can be no change without time, it is quite possible to conceive of time without change: this is persistence. Thus, change is the condition for the perception and measurement of time, its ratio cognoscendi, whereas time is the ratio essendi, the condition for the existence of change, which implies the persistence of a substrate and the succession of two different states of this substrate (pp. 82-83). The author makes a convincing analysis, although one may wonder whether the idea of time as a measure of rest does not nevertheless require the existence of movement, since for Aristotle time is a measure only insofar as it is measured by a regular movement, which serves as a standard, such as the rotation of the stars [3].
Persistence and succession are two “proximate effects of time,’ which make it possible to define time indirectly through concepts that are immediately dependent on it. The author adds the third concept of simultaneity. In so doing, he follows Kant’s analysis of the Analogies of Experience, according to which “the three modi of time are persistence, succession, and simultaneity [4]”, while making clear that simultaneity does not have the same status (it is a “proximate derivative” of time), since on the one hand the theory of relativity shows that this notion has no physical reality, and on the other hand it instead denotes the absence of time, or existence in space (pp. 136-137). Even if time is not an intuition, we can still experience the concepts of persistence, succession and co-simultaneity sensitively through music. In his remarkable reflection on the “sound world,” Wolff links his theories on music (Pourquoi la musique ? [Why Music?], Fayard, 2015) with his study of time. Music implies a succession of distinct events (the notes) with a “master sound” (tonic, tonal center, drone) that materializes persistence, an imaginary causality that represents an ordered succession (air, melody), and an interaction or agreement between sounds (harmony) that comes under the heading of simultaneity, in the knowledge that this is not an essential part of musicality. Music transforms the chaos of events into an “aesthetic order,” turning “lead (the passing of time) into gold (the pleasure of listening)” (p. 150).
Temporal order and temporal becoming
The descriptive metaphysics of time is part of the English-speaking tradition of the philosophy of time (that based on conceptual analysis, not on the philosophy of physics), in which the opposition established by McTaggart between the B series—the succession of events—and the A series—their division into past, present and future—is pivotal [5].
To situate his approach in the long history of philosophy, the author recasts McTaggart’s distinction into an opposition between “temporal order” (Aristotle, Leibniz, Kant, Russell, etc.) and “temporal becoming” (Augustine, Bergson, Husserl, Merleau-Ponty, and so on) (chap. 4). Temporal order goes from the before towards the after, like an arrow; and leads, if taken in isolation, to the representation of an unchanging world, sometimes called “eternalism,” for which the events of the world all exist in the same way, ordered in accordance with the before-and-after relationship, as if in a block (hence the alternative name “block-universe”). For succession is a relationship of order (asymmetrical and transitive), which never changes. If one event precedes another, this is eternally true. On the other hand, temporal becoming flows from the future to the past, like a river in which we are immersed (my dentist’s appointment is future, present and then past). This is the time of ordinary language, which cannot do without indexicals, starting with the “now”, the moving point around which the other two dimensions of past and future are organized. Phenomenology is concerned with temporal becoming, as experienced by consciousness.
Against the proponents of “temporal order” who seek to reduce time to space and the dynamic to the static, Wolff deconstructs the classical analogy according to which the now is no more real than the here (pp. 168-169). We can choose to change the here, by moving from one point in space to another, whereas it is impossible to change the now: if I am in Paris, I can decide to go to Lisbon for the weekend; however, if I am in 2023, I cannot choose to jump to 2024. Those who defend temporal becoming nowadays subscribe to two main conceptions: presentism (only the present exists), and the growing block-universe: only the present and the past exist, and the past is constantly expanding along with the history of the universe.
Rejecting presentism and its aporias—in particular the highly problematic theory of the non-existence of the past—Wolff follows the growing block-universe trend, in the wake of authors such as Michael Tooley (note 1, p. 190), while adding another stone to this edifice in chapter 5, which is undoubtedly the highlight of the book. To avoid the choice between eternalism and presentism, he starts from Kant’s and Frege’s analyses of existence as a second-order property (a property not of a thing but of a concept, i.e. of being instantiated) [6]. Breaking with the theory of univocity of existence accepted by these two philosophers, he distinguishes two modes of existence for a temporal entity: the “true” existence of an entity (as opposed to fiction) is the instantiation of the concept of this entity in the world (“e1”), and the “present” existence (as opposed to the past) is the “instantiation of this instantiation,” the “absolute position” (in the Kantian sense) of the first existence in the present (“e2”). This makes it possible to explain the two fundamental aspects of the past: “What is past truly exists (e1): it was. But what is past does not exist (e2) presently: it is no more” (p. 200). World time can therefore be thought of as a becoming without presentism, “the present becoming past” (p. 209), from which temporal order is obtained by abstraction.
The now
At this point the reader may think the author has reached a conclusion, but Wolff takes the analysis a step further by introducing two new meanings to the concept of present (chap. 6). In addition to the indexical present that exists for us, he brings in the idea of an objective present of the world, a non-indexical present without past or future, which would be the present of the world “without us,” “whether or not there is a subject to express or think it” (p. 213). This is what he calls the “now”. This choice of terminology is somewhat questionable, since the now is strongly associated with the indexical present in ordinary language, where it denotes the speaker’s present. However, this term is aptly explained by the return to Aristotle in the last part of the book, to that “now” (nun in Greek) which is a threshold between two states of the world, one that no longer exists, the other that does not yet exist—that now which is both always the same in its form yet endlessly different in its content [7].
Although we inevitably equate the objective present with the indexical present, which is the prism through which we perceive the world, the two must not be confused: “The form of the objective present is the fact that it exists, that it is always the property of the ‘last’ state of world history. The variable content of the indexical present is all the things that coexist. The variable content of the objective present is the instantaneous, ever-changing and ever-varying state of the world” (p. 218).
The two meanings of the present ultimately lead to two conceptions of time, which are the two sides of its definition. For us, world time is the present becoming past, but we can also think of it without us as the now becoming other, which never ceases to change into another now, as the “necessary order of the now’s alteration” (p. 234). We know that relativistic physics makes the notion of the present problematic, but the author is at pains to provide an answer to this objection. The now exists not in the form of the unique present of a universe “seen from nowhere,” but “of the infinite presents of a universe ‘seen from all sides’” (p. 171): a now diffracted “infinitely according to all ‘proper times’” (p. 264).
Unresolved issues
Thanks to its conceptual depth, this new version of the growing block-universe raises a number of questions that are likely to keep the discussion going. Here we shall mention three of them (one for each temporal dimension). First, the present. Is not the world’s conception of time “without us,” as an ever-altering now, a relapse into presentism, or a kind of “now-ism” that makes the now the “motor of time” and ultimately the only temporal reality? For Wolff, “nothing exists other than what exists now. This does not mean that only present things exist, as presentists claim: for if we assert that the present exists, we must also say, in the same breath, that the past exists, for in our shared world the present cannot exist without the past” (p. 263). Yet, in the world “without us,” is the past nothing but non-being? Is this world reduced to its present state? For “no language can express the second world, with each of its elementary states fading into non-being as soon as it is—and therefore has been—present” (p. 215). Is the fact that the dinosaurs became extinct 65 million years ago true only for our world?
This theory seems to distance Wolff’s approach from the growing block-universe, and to bring it closer to presentism, contrary to the original thrust of his argument. Hence our second question, concerning the ontological status of the past. The distinction between the two modes of existence is an undeniable step forward, but what exactly differentiates the true existence of the past from the (non-)existence of fiction? What distinguishes the Tasmanian tiger from the griffon? We would like to learn more. The question of the mode of being of the past is all the more relevant as the true existence of temporal entities—namely the “e1” that is opposed to fiction and to which the past belongs—is said to be “timeless (outside of any particular time)” (p. 198), whereas the past is always dated and localized in a particular time, in precise contrast to fiction. Furthermore, a classic objection to the growing block-universe theory is that we do not know how to distinguish the past from the present [8].
What is the difference in modes of existence between the Tasmanian tiger, an extinct species, and the Siberian tiger, which still exists in the present? Wolff settles for saying that present existence is opposed to the past, just as past existence is opposed to fiction. Here too, the reader is left wanting, as was the case with the argument that the future does not exist at all. The “proof” is that “just because we can imagine the future, it makes no sense to say that the future—which does not exist—is altered into something that does exist: the now. That would be continuous creation ex nihilo” (p. 226). Of course, provided we include in the argument that the future is a non-being, which is precisely what we are seeking to “prove”.
While the theory of the non-existence of the future is well established in the philosophy of time (it is common to presentism and the growing block-universe), it seems at odds with the world-language approach to temporal becoming, which incorporates references to the future. What are we talking about when we speak of future events (an appointment, a wedding, our death, an imminent threat, etc.)? Are we referring to chimeras? Talking about the future is certainly not the same as talking about the present or the past, but these differences should perhaps be made clearer. These brief questions merely illustrate the interest sparked by this original and consistently thought-provoking book. It is undoubtedly a key contribution to the study of time.
Francis Wolff, Le temps du monde, Paris, Fayard, 2023, 272 p., 20,90 euros.