Review of:

Philip Turetzky [1998]

Time

London: Routledge, ISBN: 0-415-13948-1 (pbk), 0-415-13947-3 (hbk)

 

Quentin Smith

Department of Philosophy, Western Michigan University, Kalamazoo, MI  49008, USA

 

Published in: British Journal of the Philosophy of Science, 2001.

I

Philip Turetzky's book TIME presents an exceptionally comprehensive and reliable history of theories of time from the pre-Socratics up to 20th century existentialist thought, Bergsonian theories and even the debate among analytic philosophers about the A and B theories of time (Mellor, Oaklander, Le Poidevin, etc.). He takes the reader up to the time of the writing of the book, the mid to late 1990s. The first characteristic of the book that should impress the reader is that Turetzky has equal expertise in such diverse thinkers as Anaximander, Aristotle, Newton, Einstein, Bergson, Husserl, Mellor and Oaklander and, indeed, has a remarkable mastery of the secondary literature on the well-known historical figures (Leibniz, Duns Scotus, Plotinus, Iamblichus, etc.) who presented theories of time.

The book contains two parts. Part One is about the history of ideas about time from Homer through Nietzsche. What impressed me most about Part One is that Turetzky concentrated on the most fundamental unifying theme in the evolution of thought about time from the early Greeks to the end of the 19th century, namely, the gradual distinction of time from change. Originally, time is identified with change (in Plato's work, time is the movement of the heavenly spheres); in Aristotle and much of the middle ages, time is identified with the numerical measure of change ("time is the measure of motion" in the wide sense of "motion" that is equivalent to change). Turetzky traces the interesting path from this Greek conception to the Newtonian theory that time is distinct from and independent of all change and measurable motion.

In the second part, "Contemporary Traditions", Turetzky concentrates on three distinct traditions: the debate about the tensed and tenseless theories of time in analytic philosophy (Turetzky correctly traces the first clear statement of the difference between A-time and B-time to Iamblichus), the phenomenological description of temporal experience in Brentano, Husserl and Heidegger, and the discussion of Bergsonian ideas of duration.

II

This organization of the book provides a good unification of the multifarious ideas about time, but could also think of another way of continuing the book after Part One. Part One discusses the emancipation of time from motion from the early Greeks to the late 19th century. One might well imagine a very different Part Two, namely, a discussion of how this tendency was reversed by Einstein in 1905 and the subsequent debates about substantivalism and relationalism in the writings of Reichenbach, Grunbaum, Earman, Friedman, Nerlich, Sklar, Newton-Smith and others. This would have made the entire book have one unifying theme. Indeed, one could have written a history showing that the very latest theories of time, in quantum gravity theory, bring (in a broad sense) the theory of the time/change relation back to its original position in Plato's Timaeus, where Plato identified time with the movement of the heavenly sphere in its revolutions around the earth". In quantum gravity cosmology, there is no time variable (in the Wheeler-DeWitt equation), and so one must pick one of the density, radius, etc., variables to do double duty as the time variable (Hartle and Hawking picks the volume of the universe as the time variable, and Vilenkin picks the density of the university as the time variable. See Smith ([1997; 1988])). As Turetzky effectively demonstrated in Part One, the tendency from Plato to the Newtonians was to free time from its dependency on change and to make time a more fundamental concept than change. But in the possible "new Part Two" I am suggesting, one could continue this history by showing how this tendency was reversed beginning with Einstein's 1905 theory. In 1908, Minkowski argued that time is an artificial conceptual abstraction from the more fundamental and metaphysically meaningful notion of spacetime. By the time that solutions to the Wheeler-DeWitt equation were developed in the early 1980s, time is in effect eliminated altogether from the physical equations, and to reintroduce time one must require one of the nontemporal physical variables to do double duty as a time variable. Alternatively, one could go to the extreme that some suggest, which is to say that time is an "illusion" and that the four-dimensional space described by the exponential growing component of the wave function of the universe is the only reality. "Time" would merely be an "appearance" generated by a timeless, mind-independent reality.

III

But this requires a caveat, since some thinkers, such as Tooley ([1997]) and Craig ([forthcoming]), have developed original and plausible neo-Lorentz theories of time. (These are distinct from the strictly metaphysical arguments for absolute  "Newtonian-like" time given in Smith [1993; 1998]). More germane to quantum gravity theories, Callender and Weingard have plausibly argued for a Bohmian interpretation of the Hartle-Hawking and Vilenkin solutions of the wave function of the universe, and this interpretation provides an independent time variable that coincides with the external time variable in the time-dependent Schrodinger equation. This in effect makes general relativity a merely phenomenological theory, with quantum gravity giving us real time. "Like Newton's absolute time, the time in Bohmian cosmology is most naturally viewed as an unobservable, physical time, arising from the basic laws" ([Callender and Weingard, 1994: 224]). Using Bohmian mechanics with its quantum potential Q, Callender and Weingard obtain dynamic variables that include a time parameter t:

 

   dχ/dt = dSχ(χ,θ); dθ/dt = dS_θ (χ,θ)).

 

Here χ is the radius of the universe and θ a spatially constant scaler field. S is the phase factor. This equation represent how the radius of the universe changes with time (thus is time is not identical with the radius of the universe, as it is some interpretations of solutions of quantum gravity equations). Callender and Weingard stress that their approach is largely speculative, given the uncertain status of quantum gravity theory at present, but Callender and Weingard seem overly pessimistic (about their own theory) in one respect, namely, in accepting the widely accepted but mistaken believe that quantum gravity cosmologies are mathematically inconsistent because they are perturbatively nonrenormalizable. It has been proven in the 1990s that perturbatively nonrenormalizability is NOT a criterion of mathematical consistency for physical theories; a case in point is that the Gross-Neveau model in 3 dimensions (GN)₃ has been proved to be exactly soluble, even though it is perturbatively non-renormalizable ([Rivasseau, 1991; Wightman, 1994]).(For references and details, see [Smith, 1999]).

Turetzky does not take this scientific/philosophy of science approach in Parts Two and Three of this book, and this is perhaps for the best if he wants to include the greatest variety of the philosophical  traditions about time, including the phenomenological and Bergsonian traditions. In a sense, this makes his book more strictly philosophical (than scientific) and makes an excellent book for an undergraduate survey course on the history of philosophies of time from the pre-Socratics (actually, Homer) to the end of the 20th century. Further, it enables him to avoids the mathematical complexities of 20th century physical theories of time that would drastically restrict the accessibility and readership of the book.

IV

If one is content to mostly neglect 20th century scientific theories of time, and the theories of time in philosophies of science such as Grunbaum, Maudlin and Callender, then there is justification to say that Turetzky's book is clearly the best book on the history of philosophies of time that has yet been written. If one were to teach an undergraduate survey course on the history of western philosophical conceptions of time, this book is the obvious choice for the text for such a course and has no real competitors.

Given Turetzky's goal of concentrating on the philosophical rather than scientific theories of time (although there is an insightful discussion of Newton's theory and its ancestors, as well as a brief but clear exposition of Einstein's STR), one might ask if there is any way this goal might be better attained than the manner exhibited in Turetzky's fine book. If one is looking for ways in which the book might have been improved, one will not find any major problems. But there are a few very minor problems.

V

For one thing, Turkey's attempt to unify his historical account by use of the heuristic tool of interpreting time "as a boundary condition of phenomena" fails for the very reason he mentions as the beginning of the book, namely, that "the key terms 'phenomena' and 'boundary conditions' each express a family of concepts" (p. 2). Turetzky then adds the promising remark that these expressions require clarification. But the clarifications only serve to make matters more obscure; for example, in clarifying "boundary condition", he says it is "a limit to phenomena", but he goes on to mention about a half-dozen different senses of "phenomena" and about half-dozen different senses of "limit". And each of these dozen senses of the terms turn out to be multiply ambiguous, e.g., one of the many different senses of "limit" is that a limit is "itself a phenomenon which somehow encompasses and constrains all other phenomena" (p. 3). Presumably, this has at least six different senses, corresponding to the different senses of "phenomena". And one needs to add to these the many different senses of "encompasses" and "constrains", producing an impenetrable Derridian jungle of equivocations upon evocations. Fortunately, Turetzky's discussion of the "boundary of phenomena" in the main body of the text is very infrequent; his few remarks on this matter are best passed over, as the phrase "boundary of phenomena" remains too vague and equivocal to shed any light on the theories he discusses. The book would be better if all the discussions of time as a "boundary of phenomena" were omitted. But this is only a minor problem with Turetzky's book since his discussion of boundaries of phenomena is infrequent and incidental to his main exposition and, more importantly, the book is well-unified by other interpretative themes. Part One is unified by the theme of how the concept of time is gradually distinguished from the conception of motion, and Part Two is unified by the two separate themes of (i) the tense versus tenseless theory of time debate in analytic philosophy, and (ii) the description of the experience of time in phenomenology and the Bergsonian tradition.

VI

The second minor problem with the book concerns Turetzky's practice of remaining as close as possible to the way the philosophers of time worded their own theories. This has the positive consequence that is book is very historically accurate. But there is in some cases a drawback to this approach, namely, when the original text is quite obscure and Turetzky does not attempt to interpret and clarify the text. For example, there are many notoriously obscure passages in Aristotle's discussion of time in PHYSICS, and Turetzky sometimes seems content to leave the obscurity untouched. For example, Turetzky writes:" Appealing to the definition of time, Aristotle says that, since time is the number of change, to be in time must be like to be in number. Things are in number when they can be counted with numbers or are aspects of numbers; similarly things are in time if they can be counted by time or are aspects of time." (p. 25)  This appears unintelligible. For example, if time is the number of change (but does the definite description "the number of change" even express a coherent concept?) then Turetzky's clause ". . . things are in time if they can counted by time or are aspects of time" would mean the same as "things are in the number of change if they can be counted by the number of change or are aspects of the number of change". Instead of reproducing Aristotle's obscurity, why not present a clear idea that is nearest to what Aristotle might have meant, if interpreted charitably? Instead of Turetzky's passage, we might write instead: "Aristotle believes that time is what is countable in changes; specifically, time is an ordered series of tokens of the same event-types in a uniform and periodic process. What is countable is the successive instantiations of the relevant event-types; for example, the risings of the sun can be numerically ordered as 1st day, 2nd day, 3rd day, etc.)"

But to Turetzky's credit, he does make important clarifications in other places, e.g., he clearly explains Sorabji's accurate interpretation that "Aristotle never [clearly] distinguished between the now as present and the now as an instant" (p. 25). One rare exception to Turetzky's historical accuracy (in his discussion of Aristotle) is quite insignificant; Turetzky says that "Aristotle claims" that "time is the most stupid of things, because it is primarily destructive...."(p. 26). Not so; Aristotle merely reports the Pyhthagorean Paron "called it the most stupid, because in it we also forget.." ([Physics, 22b, 18]). If the historical inaccuracies are as minor as these, that says something quite positive about Turetzky's historical knowledge.

VII

A third set of minor problems concerns his discussion of the German phenomenologists. Turetzky represents Husserl as significantly advancing over Brentano's defective theory of time consciousness (p. 161) but I would say that a close comparison of the original texts shows that Husserl's theory of consciousness in this respect is virtually an identical replication of Brentano's theory (see [Smith, 1981b; 1977]).

    Another problem is that Turetzky takes his source for Heidegger's theory of time from Heidegger's The Basic Problems of Phenomenology, rather than from his Being in Time. This seems a questionable approach, since Heidegger did not regard the first work as expressing a satisfactory account of his own ideas and for this reason never published it (it was only published after his death). Heidegger's own views on time appear in his most famous book, Being and Time, published by Heidegger in 1927. The view on time in Being and Time is quite different than that in Basic Problems. For example, in Being and Time, Heidegger (contra Turetzky) expressly denies that human being, or Dasein, is "that entity whose existence is characterized by intentionality" ([Turetzky], p. 183). Rather, it is characterized by disclosure [Erschlossenheit], a more basic kind of awareness; intentionally is merely a certain, derivative kind of disclosure, a making-explicit certain present-at-hand (Vorhanden) entities that are interpreted as occupying a present-at-hand "now-time". (See [Heidegger, 1972], p. 137; [1969], p .113: ; and [Smith, 1981b]).

   A different problem with his Heidegger-exposition is that Turetzky does not clearly or fully distinguish the five kinds of "time" in the broadest sense in Heidegger's theory: time (zeit: roughly, Aristotle's series of "nows"), formal temporality (zeitlichlit); authentic temporality, inauthentic temporality and Temporality (Temporalitat). For example, formal temporality consists in part of making-present, authentic temporality consists in part of envisioning possibilities of existing in one's situation, inauthentic temporality consists in part of falleness, and Temporality is "preasens" (Praesenz).

   Furthermore, it is difficult to explain Heidegger's theory of time (in the broadest sense) without pointing out that Heidegger's theory is based on an equivocation upon temporal and epistemic senses of "present", one sense being the A-determination of presentness and the other sense being what is expressed by "apparent". This equivocation arguably undermines Heidegger's theory of time ([Smith, 1986], pp. 273-281).

   Turetzky ignores the major original works in the American phenomenology of time (e.g., Peter McInerney's Time and Experience), which is unfortunate, since they are as least as significant as some of the French and German phenomenogical works he discusses.

   To emphasis once again, none of these "problems" are major problems with Turetzky's book. They are more or less of the "nit-picking" sort that do not affect the fundamental high quality of the book. This book is certainly the most accessible, comprehensive, up to date, and accurate history of the philosophy of time that has yet been written.

 

 REFERENCES

Aristotle. [1941] Physica, in Richard McKeon (ed.), The Basic Works of Aristotle. New York: Random House.

Callender, C. and Weingard, R. [1994]: 'The Bohmian Model of Quantum Cosmology', PSA 1994, Volume 1, pp. 218-227.

Craig, W. L. [forthcoming] The Tenseless Theory of Time. Dordrecht. Kluwer Academic Publishers.

Heidegger, M. [1972]: Sein und Zeit, New York: Macmillan.

Heidegger, M. [1982]: The Basic Problems of Phenomenology. Bloomington: Indiana University Press.

Heidegger, M. [1969]. The Essence of Reasons. Evanston: Northwestern University Press.