If Descartes’ account of time does presuppose the intellectual structure of his times, then this both explains and (somewhat) excuses his brevity on the topic. Moreover, it also suggests a method for interpreting his account. If Descartes assumed that his readers were familiar with the standard approaches to time, and thus simply located his own account within this basic structure, then it seems that a modern interpreter must be equally familiar with these structures. Accordingly, before looking at Descartes’ own claims about time, my first chapter will outline the historical framework that I believe his discussions presuppose.
I will attempt to sketch this framework by examining the major issues and approaches to time advocated by Descartes’ predecessors and contemporaries. It is neither feasible nor even necessary to offer a detailed account of these different approaches since it is unlikely that Descartes would have expected his readers to have exhaustive knowledge of each of these views. Insofar as I do not think an exhaustive analysis of these former accounts is needed, I will just briefly present these accounts, and will rely heavily on secondary accounts when doing so. As my goal is simply to offer a quick grounding on the intellectual backdrop in which Descartes was imbedded, I will (like Descartes) not attempt to re-invent the wheel when analyzing the accounts. As will quickly become evident, even a cursory examination of this history indicates how the various accounts tended to offer nuanced versions of broadly similar types. Given this very common framework, it would have been reasonable for Descartes to have assumed that his readers would have a passing familiarity with the general types. I will attempt to provide a contemporary reader with this same passing familiarity.
Among Descartes’ major predecessors and contemporaries, I have isolated four particularly important philosophical traditions concerning the nature of time, which I am calling: the Absolutist Approach, the Reductive Approach, the Mind-Dependent Approach, and the Dualist Approach. On the basis of this examination, I isolate three important questions concerning the nature of time which all of these traditions address in one way or another. I contend that the ways in which the previous authors responded to these questions determine fundamental features of their accounts. Given the historical importance of these questions, I will then ask these same questions (in the chapters to follow) of Descartes’ account. The three questions I will isolate are:
Is time an independent or dependent entity?
What is the relation between time and motion?
What is the relationship between time and minds?
As a result of this analysis, I will be able to show how Descartes’ brief remarks on the nature of time—when studied in an historically sensitive way—can finally be understood as making important statements, which place him in agreement with certain aspects of these major approaches and in opposition to others.
First Tradition: Absolutist Approaches to Time
According to an Absolutist Approach, time is an independent entity that cannot be ontologically reduced to anything more basic. This approach can be traced back to the ancient view that Julia Annas describes as the commonsense, Platonist view that time exists as a “mysterious cosmic entity or container.”[1] Whether Plato himself should be read as having offered an absolutist account of time is not obvious, though this suggestion has been offered by some.[2] Even if one does not agree that Plato himself offered an absolutist account of time, it is evident that such a view was around in the ancient world because Aristotle offers his own view on time in opposition to such a view. Looking at Aristotle’s implied target is thus useful for sketching an initial picture of an absolutist approach to time.
Aristotle’s approach to time, explains Annas, was motivated by his general discomfort with positing the existence of abstract objects that exist apart from concrete objects. The idea of a mysterious entity existing independently of concrete instances of timings “is already obnoxious for Aristotle, since it would mean that our statements about time were made true by an entity mysterious to us, over and beyond what we can describe in statements whose truth-conditions are given by activities like timings.”[3] As Aristotle opposed the absolutist view by himself linking time to concrete objects, his target appears to separate an account of time from an account of concrete objects or timings. Thus, the “obnoxious” subject of Aristotle’s critique appears to be anyone who would argue that time possesses an independent existence of its own.
It seems that Aristotle’s Platonist target affirms an account of time that follows some of the common idioms used to describe it. Common idioms that refer to events occurring within time would seem to imply that time exists as a type of cosmic container within which events occur. Accordingly, this absolutist (or container) view is a “commonsense view”—one that posits time to be something that exists independently from, and evidently prior to, those things that it contains. In order to exist as the container within which events can endure, it cannot be the case that the container only exists in virtue of the things that it contains.
There is ample evidence that absolutist accounts of time survived Aristotle’s reductivist attack upon them. One such account appears in the thought of Strato of Lampasces, who was the second successor of Aristotle at the Lyceum (from 233 to c. 269 b.c.e).[4] Strato describes time as being some quantity that contains motions. In The Physical World of Late Antiquity, Sambursky quotes Strato’s account of time as given by Simplicius in his commentary on the Physics.
Action and motion are quicker and slower, but the quantity in which action takes place is neither quicker nor slower but is more or less, and this is time. Day and night, a month and a year are not time, but they are light and darkness and the revolutions of the moon and the sun. Time, however, is a quantity in which all of these are contained.[5]
In defining time as being different from, and the container for cosmic motions, Strato indicates his acceptance of an absolute account of time. Strato seemed to believe that time needed be distinct from the various motions it contains in order to possess the uniform, constant flux needed to measure the various motions contained within it.[6]
Though there are others who seem to offer absolutist accounts of time after Strato,[7] the most interesting historical figure to suggest such a view (interesting in terms of his potential for influence on Descartes) is Pierre Gassendi (1592–1655). Gassendi not only frequently corresponded with Descartes, but he also challenged Descartes on the subject of time. Gassendi’s own account of time is given in his Syntagma Philosophicum.
Our opinion is that even if there were no bodies there would be both a constant Place and a flowing Time; whence it is contended that Place and Time do not depend upon bodies and are not corporeal accidents. But neither are they incorporeal accidents…they are, rather, certain incorporeal entities which differ in genus from what are usually termed substances and accidents…even if this or that substance or accident would perish, nonetheless Place would continue to be and Time to flow. Whence it is that place and time are to be regarded as true things and as entirely real...Even though...substance and accident did not exist, nevertheless [Place and Time] would exist: neither do they [i.e., Place and Time] depend upon the Intellect as Chimeras do.[8]
Given that Gassendi proposes time to be an “entirely real” entity, this text clearly indicates that even among Descartes’ most immediate contemporaries there were persons positing that time might exist as a something free from dependence on the things that endure through it. Not only did Gassendi deny that time was dependent on some substances or attributes, he was willing to grant that time exists before and after such things. He claims, “time always elapses at the same rate whether anything endures in it or not.”[9] Accordingly, Gassendi denies that the class of “being” is limited to substances and attributes as “common opinion” claims.[10] Rather, he claims that place and time are additional sorts of beings that exist independently from substances and attributes, which enable them to measure those things that endure within them.[11]
From Gassendi alone one get
s both a picture of an absolute approach to time, as well as strong grounds for assuming that this picture was one with which Descartes was familiar. According to Gassendi’s account, time and place “are to be regarded as true things” that are not dependent on minds and that would exist irrespective of substance or accidents. As such, Gassendi grants time the sort of independence toward which Aristotle’s much earlier critique was directed. Thus, it is evident that among at least one of Descartes’ closest contemporaries, there was a well-developed account of time that followed the absolutist approach.
We can now summarize different common characteristics of the absolutist traditions found in Plato, Strato, and Gassendi using the three questions from above.
Is time an independent or dependent entity? According to the absolutist, time is an independent entity.
What is the relation between time and motion? According to the absolutist, time is ontologically prior to motion and a “container” within which motions exist and are measured.
What is the relation between time and minds? According to the absolutist, time exists independent of minds. Minds exist within time and time could exist even if there were no minds.
Tradition Two: Reductive Approaches to Time
Although Gassendi’s position indicates that absolutist accounts of time endured well beyond Plato and Strato, there is also ample evidence which indicates that reductive approaches to time were the dominant position among the Pre-Cartesian philosophical traditions. According to the reductive approach, time is not an ontologically basic entity, but is instead somehow dependent upon something more fundamental. This reductive approach was favored not only by Aristotle, but also by many of the scholastics that followed him. In briefly outlining Aristotle’s reductive account (as it appears in his own works and in some of his followers), one finds both the motivations for the approach, as well as its two most common forms: celestial reductionism and relationalism.
Aristotle’s extended discussion of time occurs in the Physics IV, where he defines time as being “the number of motion in respect of ‘before’ and ‘after.’”[12] As this definition indicates, Aristotle proposed an intimate link between time and motion. Aristotle connected time to motion and therefore to the activities of the ordinary constituents of the physical world by identifying time with the ‘before’ and ‘after’ that a soul is able to apprehend by way of changes or motions. The difference that one is able to note by way of these motions allows one to enumerate a diverse collection of “nows.” Aristotle contends that the enumeration of these nows, that is, of the various states of a thing in motion, is just what time is. By identifying time with the enumeration of progressive states of physical objects, Aristotle’s account of time clearly contrasts with the absolutist picture. Aristotle suggests that time is nothing other than the motions of the physical world insofar as they give rise to an enumeration by way of rational souls noticing the changing states. Thus, Aristotle contends that one need only study the workings of concrete particulars in order to understand the nature of time. Accordingly, he denies the necessity of positing the existence of some additional, independently existing temporal container.
Though many who followed Aristotle approved of his general reductive approach to time, they disagreed about what time is, or where it is found, within the Aristotelian picture. One of the reductive strategies that received significant support is the view that time reduces to specific celestial motions, that is, “celestial reductionism.” In his article entitled “Celestial Reductionism,” Piero Ariotti argues that this view was the “prevalent conception of time” following Aristotle.[13] Ariotti defines celestial reductionism as “the view that conceives time as owing its existence and particular nature to some well specified actual motions.”[14] Ariotti argues that this was in fact the view of Aristotle himself, though this point is controversial.[15] Whether or not Aristotle himself maintained a version of celestial reductionism, some of his predecessors appear to have done so.
In the Summa, Aquinas appears to offer a version of celestial reductionism when he identifies time with an attribute of the first motion.
The true reason why time is one, is to be found in the oneness of the first movement by which, since it is most simple, all other movements are measured, as it is said in Metaphysics X. Therefore, time is referred to that movement, not only as a measure is to the thing measured, but also as accident is to subject; and thus receives its unity from it. Whereas to other movements it is compared only as the measure is to the thing measured. Hence, it is not multiplied by their multitude, because many things can be measured by one separate measure.[16]
In this text, Aquinas claims that the numbering of the first motion provides a standard according to which all other motions can be compared and counted. In other words, Aquinas attempts to grant the Aristotelian suggestion that time reduces to the number of motions without thereby conceding a multiplicity of times. This worry about “multiple” times is the natural consequent of the Aristotelian move of locating time within the motions of particular existing substances. Insofar as there are numerous movers, a reductivist following Aristotle must offer some explanation for how a multiplicity of concrete movers could still account for the existence of a singular time according to which all motions might be compared.
Aquinas noted the multiplicity of reductive times when he asserts that “number, as it exists in the thing numbered, is not the same for all; but is diverse for diverse things.”[17] Accordingly, Aquinas explains that if time were merely the number of diverse motions, then there would a multiplicity of different times corresponding to the number of each individual motion. Rather than admitting such a multiplicity, Aquinas suggests that there is a unified time provided by the first motion (as a substance to its attributes), because the enumeration of this most simple motion provides a standard measure according to which the enumerations of all other motions can be compared.
In claiming that time is referred to the first movement, Aquinas not only offers a type of celestial reductionism, but he also explains how this reduction makes time immediately dependent on the first motion. In his Commentary on the Physics at 4.17 [574] Aquinas explains, “Whatever is mutable in existence is such because of that first motion, which is the motion of the first mobile object . . . time is consequent upon only the one first motion by which all other motions are caused and measured.”[18] Given the claim that the first motion is both the cause and the measure of other motions it follows that the first motion is not merely the organizing principle according to which the times of various motions are conceived in a unified way. Rather, there would be no other motions without the first motion, and thus nothing temporal without this first motion. Time is a direct consequence of this first motion, and thus dependent on this particular motion in the same way that all other motions are dependent on the first motion as their cause. Time has an even more intimate link to the first motion, however, because time is not only caused by this motion, but it is also identical with the measure of this first motion.
Aquinas’s example shows how identifying time with the measure of specific cosmic motions enabled celestial reductionists to not only provide singular, reductive accounts of time, but also to explain how time is both continuous and regular. Time is continuous and regular because the cosmic motions are continuous and regular.
Since motion in respect to place is motion from something to something in respect to magnitude, and since every magnitude is continuous, then it is necessary that motion is consequent upon magnitude in continuity. That is since magnitude is continuous, motion is continuous, and consequently time is also continuous.[19]
Celestial reductionism thus provides an elegant solution to a number of problems which all temporal reductivists must face: It explains how time can be singular despite the fact that there are multiple motions, and it explains how time can be both continuous and regular. Despite these attractive features of celestial reductionism, the view had its critics. In the Confessions, for example
, Augustine explicitly rejects celestial reductionism. Augustine claims, “I have heard from a certain learned man that the movements of the sun, moon, and stars constitute time, but I did not agree with him.”[20] Augustine proceeds to argue against celestial reductionism on the theological grounds that it would conflict with Jos.10:12, in which it is recorded that God stopped the motion of the sun and moon and yet activity (and thereby time) continued.[21]
Though Augustine dismisses celestial reductionism as being both naïve and inconsistent with scripture, both Augustine and Aquinas’s discussions of the view show the endurance and the appeal of the approach. For those inclined to follow Aristotle’s lead in conceiving of time as being something based in the concrete world, and not as something existing as a mysterious, cosmic container, celestial reductionism offered an appealing option. Not only did this account locate time within the activity of concrete beings (namely, in celestial bodies), but since the cosmic motions were continuous and uniform, time was thereby also given a continuous and uniform character. The time of celestial reductionists earned the characteristic benefits associated with the celestial motions while also seeming to cohere with the commonsense notion that time is determined by the sun’s rising and setting.
Though celestial reductionism may have been one popular reductive strategy, there were others who accepted Aristotle’s reductive approach without arguing that time was identical to specific motions. This group, who I am calling the relationalists, denied that time was identical with motions per se. Instead, relationalists claimed that time is a relation that depended on motion as its relata. In the Physical World of Late Antiquity, Sambursky identifies Aristotle himself as a relationalist.
Descartes' Temporal Dualism Page 2