Why Time-in-thought must be an Innate Idea
Having argued that time-in-thought is a kind of idea, I can now consider what kind (i.e., fictitious, adventitious, or innate). An initially plausible interpretation might be that time-in-thought is a (fairly uninteresting) adventitious idea that we gain by observing the motion of celestial bodies (much like Suarez’s external time.) However, this interpretation is incorrect. While the chosen unit of measurement is certainly based on convention and empirical input, the idea of time-in-thought to which the unit is applied is not. To defend this claim, I will briefly present Descartes’ three different categories of ideas, since it is through considering these ideas that one learns which type could be consistent with time-in-thought. I can then move from showing why time-in-thought should be classified as an innate idea to the texts that indicate that Descartes himself assumed this classification.
Descartes’ most famous discussion of his three types of ideas is undoubtedly found in Med III’s “Trademark Argument.”
Among my ideas, some appear to be innate, some to be adventitious, and others to have been invented by me. My understanding of what a thing is, what truth is, and what thought is, seems to derive simply from my own nature. But my hearing a noise, as I do now, or seeing the sun, or feeling the fire, comes from things located outside me, or so I have hitherto judged. Lastly, sirens, hippogriffs and the like are my own invention.[14]
In this discussion, his account of innate ideas is the most obscure, whereas the other two are more accessible. Adventitious ideas are simply those ideas that one receives through input from the senses upon encountering something in the external world. As Descartes’ example indicates, one receives the idea of heat when approaching a fire. This is an adventitious idea because the idea forms independently of one’s will as a result of an external cause. By contrast, Descartes describes invented (i.e., fictitious) ideas as being those ideas that one’s mind willfully forms. For example, one first has an adventitious idea of a horse and of a horn, and then one willfully unites these two ideas to create the idea of a unicorn. Unlike either adventitious or fictitious ideas, Descartes describes innate ideas as being those ideas that “derive from my own nature.” By this Descartes means that innate ideas are not caused by the influence of any part of the created world. Innate ideas are found in created minds via the causal efficacy of the creator alone.
In the concluding sections of Med III, Descartes describes the divine causation of innate ideas specifically as it relates to his idea of God. He wonders how he might have acquired his idea of God and argues that he could not have gotten it through the senses since it never came upon him unexpectedly. He likewise argues that it could not have been formed by his own invention, since he is “unable either to take away anything from it or to add anything to it.”[15] He thus concludes that it must be an innate idea placed in him by God. This discussion is not only explicit in attributing the source of innate ideas to a divine cause; it also begins to suggest a criterion for distinguishing innate ideas from those that are either adventitious or fictitious. Adventitious ideas can be recognized as those ideas that one acquires unexpectedly, and fictitious ideas are those that one is free to alter. Though innate ideas might simply be recognized as being those ideas that meet neither of the above criteria, Descartes provides an additional means for identifying an innate idea as such.
Descartes elaborates on the unique nature of an innate idea in a letter to Mersenne (16 June 1641).
I use the word ‘idea’ to mean everything which can be in our thought, and I distinguish three kinds. Some are adventitious, such as the idea we commonly have of the sun; others are constructed or made up, in which class we can put the idea which the astronomers construct of the sun by their reasoning; and others are innate, such as the idea of God, mind, body, triangle, and in general all those which represent true, immutable and eternal essences.[16]
In this letter, Descartes’ accounts of fictitious and adventitious ideas accords with the Med III account. But his account of innate ideas goes further by explaining that innate ideas are ideas of true, and immutable essences. This agrees with Med III’s claim that innate ideas relate to one’s understanding of a thing’s nature, of minds and of truth, but the letter to Mersenne explains why innate ideas have this property. Innate ideas are truth-entailing because they are neither created by our minds nor derived from the external world. As either such process results in ideas that are limited by the possibilities of human error, neither fictitious nor adventitious ideas are guaranteed to be truth-entailing. On the contrary, innate ideas are truth-entailing because they are the only ones that are divinely caused.
Insofar as innate ideas were previously identified as being ideas caused by God, it is not surprising to learn that these ideas are ideas of truth-entailing, true, and immutable natures[17] since God is not a deceiver. What is particularly interesting about innate ideas being ideas of true and immutable natures is that this implies a test for determining which of our ideas are innate. One can analyze the content of one’s idea. If the content of the idea does not admit of alteration, and presents one with eternal truths, then one’s idea must be an idea of a true and immutable nature; hence, this idea must have been caused by God.
Before I apply this test to the idea of time-in-thought, I want to briefly clarify the connection between innate ideas, true and immutable natures, and eternal truths that I am claiming. Eternal truths are intimately connected with ideas about true and immutable natures because eternal truths are truths about true and immutable natures. In other words, the truths (which we can think of as propositions) that can be drawn from one’s idea of a true and immutable nature are eternal truths. These truths are eternal insofar as they were true of the immutable natures prior to and independently of one’s discovery of them (through analyzing our innate ideas). That is to say, they are true even when they are not known. These truths, Descartes explains in the Sixth Set of Replies, do not “‘depend on the human intellect or on other existing things’; they depend on God alone.”[18] Though eternal truths exist whether or not they are known, when they are known, this indicates one’s possession of an innate idea. So, to pull it together: true and immutable natures are what make eternal truths true, and an idea of a true and immutable nature is an innate idea.
One might recall the similarities between Suarez’s extrinsic time and Descartes’ time-in-thought and suppose that time-in-thought is more likely to be an adventitious or fictitious idea than an innate idea since these resemble Suarez’s extrinsic time. Suarez described extrinsic time as imaginary because it was an idea that one constructed by beginning with the adventitious idea of the cosmic motions and then altering the idea by supposing that this movement is “continuous, successive, and non-repetitive”[19] Through this mental alteration Suarez contends that the idea formed is able to function as an objective measure for all durations. Given the similarities between Descartes’ time-in-thought and Suarez’s extrinsic time, it is reasonable to suppose that Descartes was aware of and even influenced by Suarez’s account. Nonetheless, I do not think it is reasonable to suppose that Descartes’ time-in-thought agrees with Suarez’s account of how this idea is caused.
It seems that the idea of time-in-thought could not be caused either by input from the external world or by the willful operation of one’s reason. Time-in-thought could not be an adventitious idea unless it were an idea that Descartes acquired (independently of his will) by input from the senses. As time-in-thought’s function as the measure of all duration has led to the supposition that the idea is of an infinitely extended series of successively related parts, this does not seem to be a good candidate for an adventitious idea. From observing the motions of individual, successive durations one’s senses might gain the adventitious idea of successively related parts. As Suarez noted, however, this adventitious idea would be insufficient for one seeking a measure of all durations, because it would be limited by the finite, temporal extension of whatever mot
ion was observed.
Even if time-in-thought could not be an adventitious idea, one might have thought that it could be an idea that reason formulates by altering the idea originally given to the mind through experience. But if time-in-thought were thus a sort of fictitious idea, it would have to have a malleable nature, since a defining characteristic of a fictitious idea is that it can be changed at will according to the dictates of one’s imagination. In the idea of time-in-thought that has so far been sketched no such malleability is evident. The idea of an infinitely extended series of successively related parts is the “measuring stick” idea assigned to time-in-thought. If this is a fabricated idea, then it seems that it should be possible to alter this idea at will. Yet such alterations would seem to inhibit time-in-thought from serving its function as a universal, objective measure. If the successive parts of the measuring stick could be, for example, randomly rearranged, disordered, or perhaps spread in a non-equidistant manner, then it would lack the requisite regularity needed for an objective measure. Such a disordered idea could not serve as a measure relating all durations. Thus, it seems time-in-thought cannot be a fictitious idea.
Moreover, the mere fact that the idea of time-in-thought includes the idea of infinitely extended succession prevents Descartes from supposing that this is a created idea because Descartes denies that minds are capable of formulating a notion of infinite. In his Med III proof for God’s existence, it is God’s infinite nature that Descartes emphasizes as being the characteristic of his idea that his own mind could not have created. Descartes focuses on his idea of an infinite, supremely perfect substance and asks if there is any way that the idea of such a thing could have originated from his own imagination. In virtue of God’s infinity, Descartes concludes that it could not. He claims that “it is true that I have the idea of substance in me in virtue of the fact that I am a substance; but this would not account for my having the idea of an infinite substance, when I am finite, unless this idea proceeded from some substance which really was infinite.”[20] Descartes adds that his idea of infinite could not have arisen in the way that his ideas of rest and darkness arose; namely, via negations of his ideas of motion or light. “On the contrary,” he claims, “I clearly understand that there is more reality in an infinite substance than in a finite one, and hence that my perception of the infinite, that is God, is in some way prior to my perception of the finite.”[21] Though one might rightly note that this discussion concerns an infinite substance and not an infinite series per se, it seems that similar reasoning would imply that Descartes could not be the source of his idea of an infinite series. If Descartes cannot manufacture an idea of an infinite substance via the negation of his idea of a finite substance, then it seems that Descartes would be equally incapable of forming an idea of an infinitely extended succession from the negation of the adventitious idea of some limited duration.
One might object to this argument on the grounds that I have ignored Descartes’ distinction between the infinite and the indefinite. Perhaps, it might be claimed, we cannot form the idea of an infinitely extended succession, but we can form the idea of an indefinitely extended succession. The assumption underlying this objection is that there is a difference in kind (or a qualitative difference) between the infinite and indefinite. This objection may seem well-grounded on the distinction Descartes draws in Principles I.27. He claims, “since we are finite, it would be absurd for us to determine anything concerning the infinite; for this would be to attempt to limit it and grasp it.” Accordingly, he warns that one ought to avoid asserting of things in which we cannot recognize a limit “that it is infinite, and instead regard it as indefinite.” In regarding things in this way, Descartes says that he i) acknowledges our finitude, ii) reserves the term of ‘infinite’ for God alone and, iii) and acknowledges that in the case of all things but God, “our understanding does not in the same way positively tell us that they lack limits in some respect.” Only the divine nature is such that it positively suggests itself to be a thing that cannot be limited. All other things are such that we can only “negatively” acknowledge that if they have any limits these limits “cannot be discovered by us.”[22]
As Principles I.27 indicates, Descartes does suggest that in deference to our own finitude, we should reserve the term ‘infinite’ for God. In the 5th Replies, however, he explains that this does not mean that other things cannot be conceived of as limitless in a single respect.
In cases like the extension of imaginary space, or the set of numbers, or the divisibility of the parts of a quantity, there is merely some respect in which I do not recognize a limit; so here I use the term ‘indefinite’ rather than ‘infinite,’ because these items are not limitless in every respect.[23]
In other words, there does not seem to be a distinction in kind (or a qualitative distinction) between the infinite and the indefinite, but only a quantitative distinction. Things which are properly infinite are things which are perceived as having no limits at all. Things which are indefinite are things which are perceived as having no limit in some specific respect. Thus, in claiming that the idea of ‘time-in-thought’ contains the idea of an infinitely extended series, I suggest that the time-in-thought is an idea of limitless temporal extension, as opposed to an idea of something properly infinite which would be an idea of something limitless in every respect. Whereas God is infinite in all respects, time-in-thought is infinite in this one respect only. Though the appropriate Cartesian terminology for this kind of limitlessness is “indefinite,” I use the term to identify the fact that this succession must lack any limit. The nature of this limitlessness is of the same kind as divine infinity, except that it is an infinity which only relates to the succession being limitless in its duration (and not in every respect, i.e., God).
As a finite/limited being, it seems that I am no more capable of forming the idea of a limitless succession than I am of forming the idea of something that is limitless in every respect. Insofar as limitlessness is a perfection, and one that I lack, it seems I cannot be the cause of an idea that is limitless in any respect. Descartes suggests a very similar point in the 2nd Set of Replies.
In my thought or intellect I can somehow come upon a perfection that is above me; thus I notice that, when I count, I cannot reach a largest number, and hence I recognize that there is something in the process of counting which exceeds my powers…[he thus discovers] that this power is something which I have received not from myself but from some other being which is more perfect than I am.[24]
In other words, whenever one happens upon an idea in which the limits of one’s own nature are made evident, Descartes suggests that this discovery suggests an external cause as grounding this idea. Accordingly, for substances with finite duration to possess an idea of an unlimited duration, there must be some external source of this idea. Margaret Wilson helpfully clarifies this point.
Descartes does think his power of generating conceptions of the indefinite cannot be accounted for by his own nature, but requires the existence of something outside of himself.... Even though the number series, for instance, differs from God in not being “unlimited in all respects” … Descartes holds that his power of numbering still requires an external cause.... Thus Descartes seems to hold that merely negative knowledge that something is such that we cannot find its limits (if it has them) is sufficient to generate a causal argument [by the Causal Adequacy Principle] for some external existent. [25]
The idea of time-in-thought must be limitless in this way, or it could not measure any possible duration. Thus, it is an idea that we could not fabricate/cause from our own natures. Thus, even if the idea of time-in-thought might (more properly) be described as an ‘indefinitely’ extended series, this correction does not make it an idea that we could create, that is, a fictitious idea.
Though the arguments against time-in-thought’s being either adventitious or fictitious count in favor of time-in-thought’s being innate, Descartes offers further support for this conclusion
. In the Third Set of Replies, Descartes uses his causal adequacy principle to provide an additional criterion according to which innate ideas can be recognized as such. Descartes explains that “elements in our thought which do not resemble external objects manifestly cannot have originated in external objects.”[26] In other words, if an idea possesses features not found in any external object, then the ideas which have these features must be innate. This follows insofar as adventitious and fictitious ideas both originate from external objects—adventitious ideas as directly given, and fictitious ideas as modifications on what is directly given.
Unlike anything found in the external world, the idea of time-in-thought represents a measuring stick with necessarily related temporal parts. If the “moments” on this stick could change their positions, then it could not provide a consistent measure of durations. Indeed, in the Fifth Set of Replies Descartes points to this feature of time-in-thought when he distinguishes an idea of time from an idea of duration. Descartes complains that Gassendi tries to evade his Med III argument “by talking of the necessary ‘connection’ which exists between the divisions of time considered in the abstract” while Descartes claims that he is in fact concerned with “considering the time or duration of the thing which endures.”[27] With the distinction between duration and time-in-thought in hand, it seems that Descartes’ complaint to Gassendi is that Descartes is discussing intrinsic durations, while Gassendi is discussing time-in-thought. Every constituent of the external world is radically contingent on God’s continuous (re)creation for it to remain in existence. There are no necessary relations between the different stages of a thing’s history. On the contrary, time-in-thought appears to pick out an idea with necessarily related, successive parts. As the radical contingency of everything in the external world indicates that nothing in the external world can share this feature,[28] the necessarily related parts of time-in-thought are elements that are not (and indeed could not be) found in any objects in the external world. Thus, as an idea that includes necessarily related parts, time-in-thought must be innate.
Descartes' Temporal Dualism Page 11