Aristotle’s concept and Kant’s ‘intuition’ of time

True to his usual method, Aristotle opens his discussion of time by pointing to difficulties people experience when they think about it: ‘First, does it belong to the class of things that exist (poteron tȏn ontȏn estin) or to that of things that do not exist (ê tȏn mê ontȏn)? Then, secondly, what is its nature (eita, tis hê phusis autou)? The following considerations would make one suspect (ek tȏnde tis an hupopteuseien) that it either does not exist at all (hoti men oun ê holȏs ouk estin), or barely (ê molis), and in an obscure way (kai amudrȏs). One part of it has been (to men oun autou gegone) and is not (kai ouk estin), while the other is going to be (to de mellei) and is not yet (kai oupȏ estin). Yet time – both infinite time and the time always taken – is made up of these (ek de toutȏn kai ho apeiros kai ho aei lambanomenos chronos sunkeitai). One would naturally suppose that what is made up of things which do not exist could have no share in reality (to d’ ek mê ontȏn sunkeimenon adunaton an einai doxeie metechein ousias).’ (217b31-218a3)

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R. P. Hardie’s and R. K. Gaye’s translation, with one alteration. Hardie and Gaye translate kai ho aei lambanomenos chronos ‘and any time you like to take’, I write ‘and the time always taken’. I believe that Aristotle here contrasts time viewed as infinite, infinite both into the past and into the future, with time that is always taken as it passes. In support of this interpretation I go back to the 3^rd book of the Physics, in which Aristotle discusses infinity (to apeiron). At the end of the book Aristotle says (in Hardie’s and Gaye’s translation): ‘Time indeed and movement are infinite (ho de chronos kai hê kinêsis apeira esti), and also thinking (kai hê noêsis), in the sense that each part that is taken passes in succession out of existence (ouch hupomenontos tou lambanomenou, 208a20-21).’

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Aristotle adds: ‘Further (pros de toutois), if a divisible thing is to exist (pantos meristou, anper êi), it is necessary that (anankê), when it exists (hote estin), all or some of its parts must exist (êtoi panta ta merê einai ê enia). But of time (tou de chronou) some parts have been (ta men gegone), while others have to be (ta de mellei), and no part of it is (esti d’ ouden), though it is divisible (ontos meristou). For what is “now” is not a part (to de nun ou meros): a part is a measure of the whole (metrei te gar to meros), which must be made up of parts (kai sunkeisthai dei to holon ek tȏn merȏn). Time, on the other hand (ho de chronos), is not held to be made up of “nows” (ou dokei sunkeisthai ek tȏn nun).’ (218a3-8)

Without attempting to solve these difficulties, Aristotle goes on to discuss the nature of time (tis hê phusis tou chronou, 218a31). He notes that time is mostly supposed to be motion and a kind of change (dokei malista kinêsis einai kai metabolê tis ho chronos, 218b9-10). Against this view he raises two objections: 1. ‘The change or movement of each thing (hê men oun hekastou metabolê kai kinêsis) is only in the thing which changes (en autȏi tȏi metaballonti monon estin) or where the thing itself which moves or changes may chance to be (ê hou an tuchêi on auto to kinoumenon kai metaballon). But time is present equally and everywhere and with all things (ho de chronos homoiȏs kai pantachou kai para pasin, 218b10-13).’ 2. ‘Again (eti de), change is always faster or slower (metabolê men esti thattȏn kai bradutera), whereas time is not (chronos d’ ouk esti); for “fast” and “slow” are defined by time (to gar bradu kai tachu chronȏi hȏristai) – “fast” is what moves much in a short time (tachu men to en oligȏi polu kinoumenon)– “slow” what moves little in a long time (bradu de to en pollȏi oligon); but time is not defined by time (ho de chronos ouch hȏristai chronȏi), by being either a certain amount or a certain kind of it (oute tȏi posos tis einai oute tȏi poios).’ (218b13-18) Aristotle concludes the aporetic preliminaries with the words: ‘Clearly then it is not movement (hoti men toinun ouk estin kinêsis phaneron). We need not distinguish at present (mêden de diapheretȏ legein hêmin en tȏi paronti) between movement and change (kinêsin ê metabolên, 218b18-20).’

Aristotle opens his own account of time by stating that although time is not change, it does not exist without change (alla mên oud aneu ge metabolês); to confirm this statement, he appeals to our subjective experience:  ‘for when the state of our own minds does not change at all (hotan gar mêden autoi metaballȏmen tên dianoian), or we have not noticed it changing (ê lathȏmen metaballontes), we do not realize that time has elapsed (ou dokei hêmin gegonenai chronos, 218b21-23).

Next, Aristotle asks ‘how time appertains to movement’ (ti tês kinêseȏs estin, 219a3). He begins to answer this question by relating movement to spatial magnitude and time to movement: ‘Since what is moved is moved from something to something (epei de to kinoumenon kineitai ek tinos eis ti), and all magnitude is continuous (kai pan megethos suneches), the movement follows the magnitude (akolouthei tȏi megethei hê kinêsis); because the magnitude is continuous (dia gar to to megethos einai suneches), the movement too is continuous (kai hê kinêsis estin suneches), and because of the movement the time is continuous (dia de tên kinêsin ho chronos); for the amount of the movement that has taken place always appears to correspond to the amount of time that has passed (hosê gar hê kinêsis, tosoutos kai ho chronos aiei dokei gegonenai).’ (219a10-14; in this passage Aristotle did not allow me to keep to Hardie’s and Gaye’s translation of his text; I nevertheless acknowledge my having benefited from their effort.)

In contrast to Aristotle, Kant in his Critique of pure reason views time as primary, space as secondary.  For he views time as ‘the subjective condition (die subjektive Bedingung) under which all our intuitions take place’ (unter der alle Anschuungen in uns stattfinden  können, B49, A33), as ‘the formal condition a priori of all phenomena whatsoever (die formale Bedingung a priori aller Erscheinungen überhaupt); space (der Raum), on the other hand, as the pure form of external intuition (als die reine Form aller äusseren Anschauung), is limited as a condition a priori to external phenomena alone (ist als Bedingung a priori bloss auf äussere Erscheinungen eingeschränkt).’ Time is not subjected to any such limitation, ‘for all representations (weil alle Vorstellungen), whether they have or have not external things for their objects (sie mögen nun äussere Dinge zum Gegenstande haben, oder nicht), still in themselves (doch an sich selbst), as determinations of the mind (als Bestimmungen des Gemüts), belong to our internal state (zum inneren Zustande gehören); and because this internal state is subject to the formal condition of the internal intuition, that is, to time (dieser innere Zustand aber, unter der formalen Bedingung der inneren Anschauung, mithin der Zeit gehört) – time is (so ist die Zeit) a condition a priori of all phenomena whatsoever (eine Bedingung a priori von aller Erscheinungen überhaupt) – the immediate condition of all internal (und zwar die unmittelbare Bedingung der inneren), and thereby the mediate condition of all external phenomena (und eben dadurch mittelbar auch der äusseren Erscheinungen).’ (B50, A34, tr. Meiklejohn)

To get a clearer view of the contrast between Aristotle’ concept of time as depending on motion and motion on special magnitude, and Kant’s ‘intuition’ (Anschauung) of time as the all-embracing ‘intuition’ on which the ‘intuition’ of space is dependent, let me compare the following two passages:

Aristotle in the Physics links time to locomotion, locomotion to spatial magnitude: ‘The before and after, then (to dê proteron kai husteron), is primarily in place (en topȏi prȏton estin); and here it is by virtue of relative position (entautha men dê têi thesei). Since then the before and after is in magnitude (epei d’ en tȏi megethei esti to proteron kai husteron), the before and after must also be in movement (anankê kai en kinêsei einai to proteron kai husteron), in correspondence to those (analogon tois ekei). But the before and after is also in time (alla mên kai en chronȏi estin to proteron kai husteron), for time and movement always correspond with each other (dia to akolouthein aei thaterȏi thateron autȏn) … But we apprehend time only (alla mên kai ton chronon ge gnȏrizomen) when we have demarcated movement (hotan horisȏmen tên kinêsin), demarcating it by the before and after (tȏi proteron kai husteron horizontesˑ) … for time is just this (touto gar estin ho chronos): number of motion in respect of the before and after (arithmos kinêseȏs kata to proteron kai husteron).’ (219a14-b2, my translation)

In his ‘Transcendental Exposition of the Conception of Time’ (Transzendentale Erörterung des Begriffs der Zeit) Kant says ‘that the conception of change (dass der Begriff der Veränderung), and with it conception of motion (und, mit ihm, der Begriff der Bewegung), as change of place (als Veränderung des Orts), is possible only through and in representation of time (nur durch und in der Zeitvorstellung möglich ist); that (dass,) if this representation (wenn diese Vorstellung) were not an intuition (internal) a priori (nicht Anschauung {innere} a priori wäre), no conception (kein Begriff), of whatever kind (welcher es auch sei), could render comprehensible the possibility of change, in other words, of a conjunction of contradictory opposed predicates in one and the same object, for example, the presence of a thing in a place and the non-presence of the same thing in the same place (die Möglichkeit einer Veränderung, d. i. einer Verbindung kontradiktorisch engegengesetzter Prädikate (z. B. das Sein an einem Orte und das Nichtsein eben desselben Dinges an demselben Orte) in einem und demselben Objekte begreiflich machen könnte). It is only in time (Nur in der Zeit) that it is possible to meet with two contradictorily opposed determinations in one thing, that is, after each other (können beide kontradiktorisch-entgegengesetzte Bestimmungen in einem Dinge, nämlich nacheinander, anzutreffen sein).’ (B48-49, tr. Meiklejohn)

Kant’s concepts of ‘change’ (Veränderung) and ‘motion’ (Bewegung) correspond to Aristotle’s concepts of metabolê and kinêsis, which Aristotle introduced at the close of his aporetic preliminary (at 218b18-20), and which play central role in his own positive account of time as ‘number of motion in respect of the before and after’ (arithmos kinêseȏs kata to proteron kai husteron, 219a14-b2). The notion of ‘after each other’ (nacheinander), which Kant views as an a priori aspect of time that makes our ‘intuition’ of movement and change possible, corresponds to Aristotle’s ‘before and after’, to proteron kai husteron, which he views as dependent on movement and ultimately derived form to proteron kai husteron têi thesei en topȏi, ‘the before and after by virtue of the relative position in place’.