University of Virginia Library

TIME

The consciousness of time is inseparable from that
of change. But while the awareness of change as one
of the most pervasive and omnipresent features of
human experience is present on the lowest level of
human and also probably subhuman intelligence, the
consciousness of time, especially in its conceptual form,
appeared much later. Just as it was difficult to separate
space conceptually from its concrete content, it re-
quired a considerable effort of abstraction to differen-
tiate time from changes and events “taking place” in
it. The mythological image of time as a person which
drags all things into a ceaseless flux was the first crude
step in this direction.

Greek and Medieval Thought. A definite separation
of time from its content was suggested by the early
Pythagoreans: “Time is said to come from the Un-
limited, that is from infinite space” (E. Zeller, A His-
tory of Greek Philosophy, trans. S. F. Alleyne, London
[1881], I, 468-69). While time was no longer personi-
fied, it was still reified, and this reification was another
step toward the separation of time from its concrete
sensory content. The fact that time itself was regarded—
rather illogically—as being subject to time (as “coming
from infinite space”) clearly showed the difficulties to
which this early reification of time led. On the other
hand, the fact that some early Pythagoreans identified
time with the celestial sphere, or, more likely, with
its rotating motion, indicated their incapacity to sepa-
rate time from its content. The reference to the celes-
tial sphere and its revolving motion had far-reaching
effects on the subsequent development of the concept
of time: it focussed the attention of philosophers on
the regular periodicity of the celestial motions by
which time can be measured, and thus it deepened the
distinction between the qualitative content of time and
its metrical aspects.

The correlation of time with spatial motion became
the source of the relational theory of time according
to which “time is nothing by itself” (Lucretius, De
rerum natura, I, 459f.) and cannot be separated from
concrete changes occurring in it. Finally the alleged
inseparability of time from spatial displacements
created the tendency to exaggerate the analogy be-
tween space and time and, eventually, to spatialize
time altogether and thus virtually to eliminate it; this
extreme tendency is very conspicuous in the Eleatic
school: the sphere of Parmenides is timeless because
of its exclusively spatial and, consequently, immutable
character. Similarly, Zeno's four arguments against the
reality of motion (and, implicitly, against the reality
of time) were based on the assimilation of time to a
geometrical line. According to Zeno, temporal inter-
vals are adequately symbolized by spatial segments;
both are divisible ad infinitum, and to the point-like
extremities of linear segments correspond the dura-
tionless extremities of temporal intervals—instants. The
impossibility of building motion from motionless posi-
tions, and durations from the durationless instants,
follows naturally.

Eleatism was the metaphysics of timeless Being in
its most radical form; it exerted a powerful influence
on the subsequent history of Western thought, even
though it has never reappeared in such extreme form.
In other words, time and becoming, instead of being
completely eliminated in the Eleatic fashion, retained
their existence, even though it was of an inferior and
less dignified kind than that of immutable Being. This
can be seen clearly in the atomists; although they did
not deny the reality of time and motion, they did not
include them among their first principles which, ac-
cording to them, were matter and space only.
Lucretius' view that “time is nothing in itself,” quoted
above, was an echo of Epicurus' view that time was
no more than an “accident of accidents” (σύμτωμα
σύπτωμάτον
since its existence was merely a function
of the changing configurations of atoms. This was
probably the view of the early atomists as well; ac-
cording to Sextus Empiricus, Democritus regarded time
as “an appearance presenting itself under the aspect
of day and night”; if he called time “uncreated,” he
meant by it that motion (on which, in his view, time

depended) is without beginning. With such a view of
time and with their anticipation of the law of constancy
of matter, the atomists greatly strengthened the static
and substantialist modes of thought.

The antisubstantialist trend in Greek philosophy was
represented by Heraclitus of Ephesus, a philosopher
of “becoming” par excellence. In his opposition to the
Eleatics, he went much farther than the atomists who,
while admitting the reality of motion, still retained its
immutable vehicle, i.e., substantial matter; for their
atoms remain eternally the same in the successive
positions of their trajectories. Heraclitus' denial of the
immutable vehicle of motion followed from his insis-
tence on the radical fluidity of everything and on the
irreversibility of becoming: “You cannot step twice into
the same river.” For the motion of immutable particles
Heraclitus substituted the dynamic unity of process in
which each momentary phase was continuously trans-
formed into its “opposite,” that is, into a subsequent,
qualitatively different phase. Heraclitus was apparently
aware that the continuity of change (his dynamic
“unity of opposites”) resists the usual conceptual treat-
ment and even a strict application of the law of con-
tradiction: “We step and we do not step into the same
river; we are and we are not” (frag. 81). This clearly
anticipated the future Hegelian view of becoming as
a synthesis of being and nonbeing.

Yet, Heraclitus' view was not free of spatial imagery,
which was hardly compatible with his insistence on
the qualitative aspect of time and its irreversibility.
This was shown by his belief in the Great Year, i.e.,
the periodic recurrence of all events in the same order.
This year, for Heraclitus, was equal to 10,800 years
(according to another source 18,000 years). According
to the testimony of the Stoics and of Simplicius (whose
reliability on this point has been questioned by
Friedrich Schleiermacher, Ferdinand Lasalle, John
Burnet, Geoffrey S. Kirk), it measured the period
separating two successive conflagrations in which the
old world perishes and a new one is reborn. Heraclitus'
idea of cyclical becoming was a culmination of the
early pre-Socratic views about the periodicity of the
worlds. The view of Anaximander, Anaxagoras, and
Empedocles was that the existing universe is the result
of the differentiation of the original chaos—watery,
fiery, or qualitatively undetermined—into which it
would eventually return and from which a similar
universe will emerge. In such view the successive cos-
mic cycles were similar in their general features only,
not in all their specific details; but the latter view,
upholding a complete identity of the successive cycles,
emerged soon. This was the idea of eternal recurrence
of everything which some Pythagoreans accepted,
influenced probably by their identification of time with
the circular motion of the heaven: “Everything will
eventually return in the self-same numerical order, and
I shall converse with you staff in hand, and you will
sit as you are sitting now, and so it will be in everything
else, and it is reasonable to assume that time too will
be the same” (The testimony of Eudemus of Rhodes;
cf. H. Diels and W. Kranz, Die Fragmente der
Vorsokratiker, 6th ed., Berlin [1951], 58B34). This was
also the view of Archytas of Tarentum who defined
time as “the interval of the universe.”

The subsequent development of Greek, medieval,
and modern philosophy was largely dominated by the
contrast between the timeless realm of Being and the
temporal realm of change; in this sense it was a contin-
uation of the dialogue between Parmenides and
Heraclitus. In most philosophical systems Being was
endowed with a more dignified status of the true reality
of which the temporal realm is merely a pale, shadowy
replica. For Plato, in the Timaeus, the basic reality
belongs to the timeless essences (Ideas) while the
temporal realm is that of ceaseless change, generation,
and decay; time itself is of derivative nature, being
merely a “moving image of eternity.” To this meta-
physical dichotomy of Being and Becoming, of perfec-
tion and imperfection, corresponds the epistemological
dichotomy of two kinds of knowledge—true knowledge
whose object is the immutable realm of Ideas, and mere
opinion, concerning the temporal realm. In the philos-
ophy of Aristotle the timeless Ideas of Plato were, so
to speak, compressed into one single entity—God, the
immovable source of every motion. Like Plato,
Aristotle held the relational view of time; time is
inseparable from motion for without motion (in the
broader Aristotelian sense of change) there would be
no time. But while Aristotle's Prime Mover has all the
attributes of the Eleatic One, his view of the physical
world—or at least of its sublunar part—was similar to
the view of Heraclitus. Aristotle rejected the atomistic
explanation of qualitative change and diversity by the
displacement of homogeneous and unchangeable ele-
ments; he denied the existence of atoms and of the
void, and reaffirmed the reality of qualitative change.
He viewed the four sublunar elements as mutually
transformable in a way analogous to the Heraclitean
transformation of opposites. Every such transformation,
including even change of position, implies a transition
from potentiality to actuality; only the Unmoved
Mover is exempt from this passage. In introducing the
concept of not-yet-existing possibility and in insisting
on the contingency of the future, Aristotle came very
close to the idea of an “open future,” which is the
central theme of modern process philosophy.

It must also be noted that in spite of his insistence
on the inseparability of time and motion, Aristotle was

careful enough not to identify them. Since there are
various motions of different speeds occurring simulta-
neously, “the time is absolutely the same for both”
(Physics, IV, 14). There are thus absolutist elements in
Aristotle's view of time which vaguely foreshadow
Newton's view. This is also clear from his comment
on his own definition of time. After defining time as
the “numerical aspect of motion with respect to its
successive parts,” he raises the question whether time
can exist without the counting activity of mind; and
his answer is affirmative: time is numerus numerabilis,
i.e., an objective reality susceptible of being counted
but independent of the act of counting, consequently
independent of the existence of the counting mind. The
sphere of the fixed stars represents the absolutely uni-
form cosmic clock by which time is measured; its
perfectly uniform rotation is, within the realm of
change, the closest imitation of the immutability of
the Prime Mover.

Aristotle apparently also accepted the idea of eternal
return of all the events, at least if we accept his
authorship of the following passage in Problemata:
“Just as the course of the firmament and each of the
stars is a circle, why should not also the coming into
being and the decay of perishable things be of such
a kind that the same things again come into being and
decay?” (The Works of Aristotle, ed. W. D. Ross, Oxford
[1923], VII, 916a). Aristotle realized that the cyclical
character of becoming would imply a relativization of
succession: if the Trojan War will inevitably recur, then
in a sense we are living “prior” to it. The author of
Problemata, however, refused to accept the ultimate
consequence of the idea of eternal recurrence: “To
demand that those who are coming into being should
always be numerically identical, is foolish” (ibid). Like
Plato, Aristotle associated the cosmic period (“the
Great Year”) not with a periodically recurring universal
conflagration, but with a return of all celestial bodies
to the same configuration. The idea of any cosmic
cataclysm was incompatible with Aristotle's belief in
the incorruptibility of the celestial clockwork.

The cyclicity of time was upheld also by the Stoics.
According to them, at the end of each cosmic cycle
the universe is dissolved into the original fire. This will
coincide with the beginning of another cycle in which
the events of the previous cycle will be reconstituted
in all their details and in the same order. But Stoics
followed Aristotle by believing that another Socrates
who will marry another Xantippe and be accused by
another Meletus will not be numerically identical with
the previous Socrates since numerical identity implies
an uninterrupted existence. Some younger Stoics, in
conceding small differences between successive recur-
rences of Socrates, gave up the circularity of becoming
in all but name. Like Aristotle, the Stoics also specu-
lated about the paradoxical nature of the present
moment; according to Plutarch, Chrysippus de-
nied the infinite divisibility of time, i.e., he accepted
the existence of temporally extended moments,
thus curiously anticipating the modern hypothesis of
“chronons.”

Although Plotinus' Ineffable One possesses all the
attributes of the Eleatic Being, he retained change and
time on the lower phenomenal level. He tried to make
the relation between the temporal and timeless level
more intelligible by his idea of emanation, i.e., by the
process of degradation by which the lower degrees of
reality proceed from the higher ones. This idea was
implicitly present in Plato's view of the realm of
change which “never truly is,” forever oscillating be-
tween Being and Nothingness. According to Plotinus,
change and time appear on the second level of ema-
nation with the World Soul in which individual souls
are contained. Unlike the Divine Intellect at the first
level of emanation, souls are unable to grasp the time-
less truth instantaneously, but only gradually, step by
step, in a laborious process of reasoning. Succession
and change are thus mere results of human inability
to grasp everything at once. As in Plato, time is “the
moving [and therefore imperfect] image of eternity”;
but “motion” is understood by him in a psychological
sense, as “movement of the soul”; without this move-
ment time would disappear (Enneads, III, 7, 12). From
this correlation of mind and time it follows that when-
ever there is time, there is mind at least in a rudi-
mentary form, and vice versa. In this feature Plotinus'
thought is near to modern temporalistic panpsychism
(Bergson, Whitehead); but by his concept of timeless
truth and by his adherence to the cyclical theory of
time he stands at the opposite pole.

The Greek dualism of the timeless realm of perfec-
tion and the changing realm of decay, with the con-
comitant contrast between timeless divine insight and
temporal (therefore incomplete) human knowledge
dominated all medieval thought, Christian, Jewish, and
Islamic. There were only a few theologians who did
not accept predestination as an inevitable consequence
of the time-transcending divine knowledge which em-
braces the totality of all successive events in one single
act—totum simul. In the thought of Saint Augustine
there were the same two trends as in Plotinus: on one
side, time was characterized as “distension of soul”
(Confessions, Book XI) and thus correlated with
psychological reality. Augustine's description of our
consciousness of time belongs to the finest and subtlest
pieces of introspective analysis. On the other hand,
again like Plotinus, he excluded time from the highest
level of Being; time was created by God with the

creation of the world: Non in tempore, sed cum tempore
finxit Deus mundum (De civitate Dei, XI, 5).

Saint Thomas equally stressed the immutability of
God (Summa Theologica, Qu. 9). It would seem then
only consistent for Saint Thomas to accept complete
predestination (Qu. 22, 23, 24). It was exceedingly
difficult to reconcile this view with the freedom of will
which he postulated on ethical grounds. More consis-
tent on this point were the Protestant reformers of the
sixteenth century who did not hesitate to negate free-
dom completely in the name of divine omniscience and
predestination. The Greek influence can be seen also
in the fact that some Christian thinkers, like Origen,
accepted the eternity of the world and even
metampsychosis (transmigration of souls); even Saint
Thomas was aware that the Aristotelian proof of the
Prime Mover did not imply the creation of the world
in time, the truth of which must be accepted on faith,
but cannot be proved (ibid., Qu. 46).

Even the idea of eternal return did not completely
disappear during the Middle Ages as is shown by the
decree of 1277 which threatened excommunication of
those who accepted the Neo-Platonic idea of a Great
Year lasting 36,000 years. It is true that because of the
Judeo-Christian emphasis on the irreversibility of cos-
mic and human history this doctrine was foreign to
that period: thus even Origen rejected the idea of
eternal recurrence because of its incompatibility with
human freedom, while Augustine rejected it on the
ground that the incarnation of Christ could occur only
once. Thomas Aquinas pointed out that the cyclical
view of time implies the re-creation of numerically
identical individuals—an operation which because of
its intrinsically contradictory character is even beyond
God's power. But neither Duns Scotus nor William of
Ockham shared Thomas' view. Nicolas Bonnet and
François de la Marche insisted on God's power to
restore any past motion, and consequently, any past
interval of time. Since the restoration of any past
interval of time implies the concomitant elimination
of that portion of the past which separates the re-
created interval from the present moment, this claim
was in direct opposition to Thomas' view of the
intrinsic indestructibility of the past which even God's
omnipotence is unable to change: Praeterita autem non
fuisse contradictionem implicat (Qu. 25, art. 4).

Time in Classical Science. While the time of the
Aristotelian and medieval cosmology was relational, it
was still uniform and in this sense universal since it
was physically embodied in the uniform rotation of
the sphere of the fixed stars which represented the
absolute cosmic clock. But with the removal of this
privileged cosmic clock by Giordano Bruno, the unity
and uniformity of time was greatly compromised as
long as time was still regarded as inseparable from
motion, in the sense of the relational theory. For what
becomes of the unity and uniformity of time, if there
is no uniform cosmic clock by which time can be
measured? There are only two ways to avoid this
difficulty: either to accept fully the consequence of the
relational theory and to concede that without the
privileged cosmic clock there should be as many times
as there are motions—tot tempora quot motus; or to
give up the relational theory altogether, that is, to
make time completely independent of any concrete
physical motion; only in this way would the unity and
the uniformity of time not be affected by the diversity
and variability of physical motions. It was the second
solution which was gradually adopted by the incipient
modern science. This separation of time from its physi-
cal content was made easier by the fact that doubts
about the uniform cosmic clock began to arise even
prior to the elimination of the last celestial sphere. The
fact of the precessional motion, already known to the
Greek astronomers, made it necessary to postulate an
additional sphere beyond the eighth sphere; only to
this ninth sphere—and not to the sphere of the “fixed
stars”—did the truly uniform revolving motion belong.

Further observations raised the doubt whether any
uniformly running celestial clock exists at all in nature.
Doubts of this kind were expressed by Nicolas Bonnet
and Grazadei d'Ascoli in the fourteenth century; they
nevertheless insisted that the existence of true mathe-
matical time does not depend on the existence of such
a clock. Similarly, Bernardino Telesio in his De rerum
natura... (1565), though he retained the Aristotelian
cosmology, held that time is logically prior to motion
and change; while motion cannot exist without time,
time which, according to him, exists by itself (per se),
can exist without motion. A similar foreshadowing of
Newton's concept of absolute time can be seen in the
thought of Francisco Suárez, even though he too
retained the Aristotelian cosmic clockwork. He distin-
guishes two kinds of duration: “flowing imaginary
extension” (spatium imaginarium fluens), which flows
uniformly (immutabile in suo fluxu), and concrete
change which coexists with it and, so to speak, fills
it (quasi replens). Thus the distinction between time
as a homogeneous container and its concrete changing
content is clearly drawn; the former is intrinsically
irreversible, the latter is not (Disputationes meta-
physicae, C. L. sec. IX, 15).

But even after the definitive removal of the celestial
clockwork, the concept of absolute time was formed
only gradually and after some hesitation. This is clear
in the thought of G. Bruno, in particular in articles
38-40 of his Camoeracensis acrotismus seu rationes
articulorum physicorum adversus Peripateticos (Witten-

berg, 1588). Certain of its passages show that Bruno
was leaning toward the relational theory of time as,
for instance, when he claims that there are as many
times as there are stars (tot tempora quot astra). On
the other hand, guided by the analogy of infinite space
of which particular spaces are mere parts, he speaks
of universal time (tempus universale) of which particu-
lar durations are finite portions. Time would exist even
if all things were at rest and motionless; against
Aristotle, Bruno holds that change is a necessary condi-
tion for the perception of time, but not for its existence.

Similar hesitancies may be traced in the thought of
Pierre Gassendi. In his Philosophiae Epicuri Syntagma
in 1649, only six years before his death, he speaks of
time in the characteristically Epicurean way as an
“accident of accidents,” that is, accidens accidentium.
Against this relational view of time, Gassendi equally
unambiguously insists on its absolute and independent
nature, e.g., when in his polemic with Descartes he
says: “Whether things are or not, whether they move
or rest, time always flows at an equal rate.” This sen-
tence occurs almost verbatim in the passage of Isaac
Barrow, Newton's tutor (Mathematical Works, ed. W.
Whewell [1860], II, 160f.), where it is stated that mo-
tion presupposes time, but not vice versa, and that time
continues to flow even if all things stand still. Gassendi's
influence on Barrow and Newton is also clear in his
view linking the infinity of space and time with the
divine omnipresence and everlasting duration, and his
insistence that both time and space existed prior to
the creation of the world (Syntagma philosophicum,
Opera omnia, Lyons [1658], I, 183, 225). Newton's
characterization of time, in the scholium of his Philos-
ophiae naturalis principia mathematica (1687), was the
culmination of the process by which the concept of
time was separated from that of concrete physical
change:

(Andrew
Motte's translation, revised by Florian Cajori).

For more than two centuries this concept of time
remained practically unchallenged by physicists; James
Clerk Maxwell's definition of time in his Matter and
Motion (1877) is identical both in spirit as well as in
letter with that of Newton.

Time in Modern Philosophy. Modern views of time
(1500-1900) were shaped by the merging of two
influences: of the previous philosophical tradition and
of the nascent classical science. The Greek and medie
val dualism of two realms, eternal and temporal, was
retained in various systems of pantheistic monism and
its echoes can be found in other systems too. The
transcendent eternity of the medieval God was re-
placed by the impersonal immanent order of nature
which was as much beyond time and change as the
Eleatic Being, Plotinus' One, or Aristotle's and Aquinas'
God. From Giordano Bruno to F. H. Bradley this basic
pattern remained the same. “Thus also the divine mind
contemplates everything in one altogether simple act
at once and without succession, that is, without the
difference between the past, present and future; to Him
all things are present” (G. Bruno, Opera latine con-
scripta, Florence [1889], I, 4, pp. 32-33). “In eternity
there is no 'before' and 'after'; for it follows exclusively
from the divine perfection that God's decrees cannot
be different and could not have been different” (B.
Spinoza, Ethica, I, prop. 33).

The second quotation shows that the immutability
of the eternal order of nature implies the strictest
determinism. In this respect the ancient deterministic
tradition was strengthened by the mechanistic physics
of the seventeenth century. Galileo, like Bruno before
him and Spinoza after him, upheld the dualism of
timeless divine perfection and of imperfect, time-
consuming human knowledge: “We proceed in step-
by-step discussion from inference to inference, whereas
He conceives through mere intuition.... The divine
intellect... grasps the essence of the circle without
any temporal discourse (senza temporaneo discorso) and
thus apprehends the infinite array of its properties”
(Opere, Florence [1855], VII, 129). Galileo still speaks
of God; Spinoza speaks of Deus sive natura, while in
Laplace the timeless order of nature is already thor-
oughly secularized and depersonalized: what was the
omniscient divine insight in theology becomes in his
thought the universal cosmic formula containing all the
details of the cosmic history—past, present, as well as
future (Essai philosophique sur la probabilité, Paris,
1814).

Neither Bruno nor Spinoza, nor certainly Laplace,
ever denied temporal succession on the “lower” or
phenomenal level; it was only on the “higher” level
of the ultimate reality that time was abolished. This
dualism of two realms, timeless and temporal, was
retained by post-Kantian idealism. It was prepared by
Kant's view that time is a mere form of sensibility,
applicable legitimately only to the phenomenal, but
not to the noumenal realm. This explains why the
“Absolute Ego” of Fichte, in spite of his verbal em-
phasis on its becoming (Werden) and activity (Urtätig-
keit), remains timeless (cf. Grundlagen der Wissen-
schaftslehre, Berlin [1845], p. 217: Für die blosse reine
Vernunft ist alles zugleich). From such a point of view

it was only consistent for Fichte to adhere to the most
rigorous form of determinism (Die Bestimmung des
Menschen, Sämtliche Werke, Berlin [1845], II, 182-83),
while Kant used Laplacean language prior to Laplace
when he claimed that a complete insight into the
character of man would make his thoughts and actions
as predictable as the solar and lunar eclipses (Critique
of Practical Reason, trans. T. K. Abbot, 6th ed., London
[1909], p. 193).

Schelling's view of time is similar, at least in that
first phase of his thought which accounts for the close
kinship of his Identitätsphilosophie with the thought
of Bruno and Spinoza. The position of Hegel was far
more ambiguous. On one side he stressed explicitly his
agreement with Heraclitus; on the other side, he
stressed the timelessness of his Absolute Idea. Hence
two divergent interpretations of Hegel's dialectics: one
interpreting it as the dynamic, historical process
(Benedetto Croce, J. N. Findlay), the other, represented
mainly by McTaggart, according to which the dialec-
tical movement is merely in our mind, being nothing
but a series of successive approximations by which we
come closer to the timelessly realized “Infinite End,”
or Absolute Idea (J. M. E. McTaggart, Studies in the
Hegelian Dialectics, 2nd ed., Cambridge [1922], p. 171).

On the other hand, Schopenhauer's view of time was
quite unambiguous. Under the influence of Kant, he
regarded time as only phenomenally real; the thing-
in-itself which, according to him, is the Universal Will,
is, despite the apparently dynamic connotation of this
term, beyond both space and time, and he explicitly
assimilated it to the Eleatic One and All (ἕν καὶ πα̃ν).
Only later, in the second edition of his main work
(1844), did he realize that this view is incompatible
with another of his basic claims, viz., that we directly
intuit the cosmic Will in our own consciousness; how
can we perceive the timeless reality directly through
our essentially temporal introspection? He then cor-
rected his view by saying that the will of which we
are aware is not the thing-in-itself, but an appearance,
even though somehow more basic (Urphänomenon)
than other appearances. The same distinction between
temporal appearances and the static substratum
underlying them is found in F. H. Bradley, one of the
most outspoken defenders of static monism in the
twentieth century. In his main book, Appearance and
Reality (1893), he tries to show the contradictory and
therefore unreal character of change and of time as
well as of diversity in general; the transcendent Abso-
lute must be free of these contradictions.

The denial of time was frequently but not always
associated with monistic tendencies as different kinds
of static pluralism show. That the dynamic character
of Leibniz's monad is more apparent than real is clear
from its nature: the substance which contains in itself
all its future states as its own predicates (Discours de
la métaphysique, 8). His view that somebody with a
sufficient insight “would see the future in the present
as in a mirror” (“On Destiny or Mutual Dependence,”
Leibniz Selections, ed. P. P. Wiener, New York [1951],
p. 571 followed from his theory of pre-established
harmony and fully anticipated the passages of Kant,
Fichte, and Laplace, quoted above. Far more explicit
was the elimination of succession and change in J. F.
Herbart and J. M. E. McTaggart. Herbart's immaterial
units, Die Realen, are qualitatively different, but
absolutely immutable; the illusion of succession and
change arises because to our shifting attention they
appear in different aggregations. In McTaggart's
monadism true reality belongs only to a timeless series
of which the temporal series is merely apparent
perspective representation. More recently, Bertrand
Russell's “logical atomism” bears a clear similarity to
the static pluralism of Herbart, as one historian of
Anglo-American pluralism has noted (Jean Wahl, Les
philosophes pluralistes d'Angleterre et d'Amérique,
Paris [1920], p. 217). Wittgenstein's explicit denial of
the passage of time (Tractatus Logico-philosophicus
[1921], 6. 3611) is a consequence of his logical atomism.

These prevailing static tendencies explain why the
concept of absolute time, upheld by Gassendi and
Newton, has not been accepted by philosophers as
unanimously as it has been by scientists. Closest to
Newton's view was John Locke; but even Locke, in
pointing out the impossibility of comparing two
successive intervals of duration (which cannot be
superposed because of their very succession), antici-
pated the later criticisms of Bergson and Poincaré in
this regard. The most outstanding opponent of Newton
was Leibniz, who was engaged in a long polemic with
Newton's disciple, Samuel Clarke, about the status of
space and time; Berkeley's objections were directed
mainly against the concept of absolute space.

Both Berkeley and Leibniz upheld the relational
theory of space and time; time is “the order of succes-
sion of perceptions,” and as such it is inseparable from
concrete events. From this standpoint the “flow of
empty time” is without meaning. But while Berkeley
claimed that the infinite divisibility of change and time
(both being inseparable) is a mere fiction, since math-
ematical durationless instants are never perceptible
and are therefore unreal, Leibniz—like Descartes—
believed that both time and any concrete change is
divisible ad infinitum, i.e., consists of ever-perishing
instants. (It should be recalled that the alleged inde-
pendence of perishing temporal instants was used by
Descartes as the basis for his view that the world is
maintained in existence by continuous divine creation.)

While David Hume accepted Berkeley's view of
indivisible temporal moments (minima sensibilia), Kant
sided with Leibniz in accepting the mathematical
continuity (infinite divisibility) of all phenomenal
changes. Thus for Berkeley and Hume, time shared the
discreteness of perceptual changes, while for Leibniz
and Kant concrete changes shared the infinite divisi-
bility of mathematical time. Locke adopted an inter-
mediate position in drawing the distinction between
immediately experienced qualitative duration and the
homogeneous duration of the physical world (Essay
Concerning Human Understanding, Book II, Ch. 14).
This distinction became the ground for another widely
accepted distinction between the durational “specious
present” in psychology and the mathematical present
of physical and physiological time. On this point both
Leibniz and Kant remained completely Newtonian and
Cartesian.

The introspective approach to the problem of time,
initiated by Locke, Berkeley, and Hume, led to two
divergent developments: (1) to Kant's epistemological
analysis of time in the Critique of Pure Reason, and
its subsequent modifications in neo-Kantianism and
phenomenology; (2) to the systematic investigation of
temporal awareness in the empirical and experimental
psychology of the nineteenth century. According to
Kant, time is an a priori form of inner—and indirectly
of outer—sense which is both “empirically real and
transcendentally ideal”; it guarantees by its own nature
the a priori and synthetic character of arithmetical
operations, whose universal validity is independent of
experience precisely because they take place in the
ideal medium of time. But while time is a necessary
condition of all experience—both introspective and
sensory—it does not apply to transcendent “things-
in-themselves,” including our “intelligible character”
which underlies our “empirical ego.” In phenome-
nalizing both physical and psychological time, Kant
greatly strengthened static modes of thought as the
subsequent development of German philosophy
showed.

Empirical psychologists in the nineteenth century
were opposed to Kant's a priori view of time; they
pointed out that the consciousness of time is subject
to development and to individual and even pathologi-
cal modifications. This view was strengthened by the
theory of evolution and its applications to psychologi-
cal phenomena; Herbert Spencer's Principles of Psy-
chology (1855) contains long polemical passages show-
ing the incompatibility of Kant's view with the
observations of genetic psychology and psychopathol-
ogy. But despite their opposition to Kant, empirical
and genetic psychologists eventually reinforced the
tendency to phenomenalize time and thus to weaken
its ontological status. Arthur Schopenhauer's combina-
tion of the Kantian and of the empirical-psychological
approach was only apparently paradoxical; he saw in
the abnormal modifications of temporal awareness an
additional corroboration of the phenomenal, and,
ultimately, of the illusory character of time.

This is related to the fact that the theory of evolu-
tion, in spite of its emphasis on the historical aspects
of reality, was not—in its initial impact at least—
opposed to the static and substantialistic view of the
world; on the contrary, since for some time it even
strengthened it. Darwin's theory of the origin of species
was strictly mechanistic and in this way fitted perfectly
into the Laplacean framework of classical physics.
Herbert Spencer, unquestionably the most influential
philosophical interpreter of evolution in the last cen-
tury, made an ambitious attempt at deriving “the law
of evolution” from the law of conservation of energy.
This law itself was regarded by him, as well as by
Helmholtz, Häckel, Ostwald, and others, as the basis
of the law of causality. Conversely, classical principles
like ex nihilo nil fit and causa aequat effectum guided
Robert Mayer (1814-78) in his experimental search for
the law of the conservation of energy. Friedrich
Nietzsche, in spite of his contempt for static concepts
such as “substance,” “Being,” and others, did not find
it incongruous to combine the evolutionary philosophy
of Overman with the eternal return of all the events
(Die ewige Wiederkunft der Gleichen) in which becom-
ing, in virtue of its own circularity, was subordinated
to Being.

Time in Contemporary Philosophy and Science. The
radical reaffirmation—or as George Boas called it—the
“acceptance of time,” had to wait until the end of the
last century. The main intellectual obstacle to it was
the static determinism of the Spinoza-Laplacean type,
which only a few “heretical” thinkers dared to ques-
tion. Among them was Charles Renouvier who
suggested the existence of absolute beginnings (les
commencements absolus) in nature; Émile Boutroux
who in his De la contingence de la nature (1874)
suggested that physical determinism is valid only on
the macrophysical scale and that there may be micro-
physical indeterminations too small to be detected by
the methods available at that time (op. cit., Ch. IV).
C. S. Peirce expressed a similar view about the merely
approximative character of classical determinism (“The
Doctrine of Necessity Examined,” The Monist, 2 [April
1892], 321-37). Meanwhile William James also argued,
as Peirce had, for the objectivity of the chance-element
in nature (“Dilemma of Determinism,” 1884); his re-
jection of determinism, though motivated mainly by
ethical reasons, was also based on his rejection of the
timeless “block-universe” which strict determinism

implies, and which is incompatible with genuine
plurality as well as with real succession.

A far more systematic formulation of James's
pluralistic temporalism took place later, in his A
Pluralistic Universe (1909) and his posthumous Some
Problems in Philosophy (1911). In these books James's
debt to Renouvier is still acknowledged, but far more
decisive and explicitly acknowledged was the influence
of Henri Bergson. In his first book Essai sur les données
immédiates de la conscience (1889), Bergson reached
a conclusion similar to a pivotal idea in James's Princi-
ples of Psychology (1890), namely, the continuity of
introspective experience—“the stream of conscious-
ness” or “true duration” (durée réelle)—which both
thinkers stressed against artificial conceptualization and
atomization. (It is fair to stress that some of the philo-
sophically most important sections of Principles of
Psychology had been published previously in Mind
[1884] under the title “On Some Omissions of Intro-
spective Psychology.”) The dynamic continuity of
psychological time is both unity and diversity; but it
is neither the abstract homogeneous unity of mathe-
matical time nor the dust-like multiplicity of the
externally related durationless instants; it is the mnemic
continuity in which no sharp separation can be drawn
between the successive phases, despite their qualitative
heterogeneity.

In his later books Bergson generalized his intro-
spective analysis by applying its results to duration
in general. Every duration, he held, is essentially in-
complete in the sense that each of its moments intro-
duces an element of novelty not contained in the past.
In ignoring this irreducible element of novelty—
previously stressed in Boutroux's contingentism and
Peirce's tychism—radical determinism as well as radi-
cal finalism virtually and sometimes even explicitly
eliminate time altogether in fusing the successive
phases into a single instantaneous unity of the
Laplacean formula or of the immutable Absolute. In
such a “block universe”—whether of the naturalistic
or idealistic kind—“everything is given” (tout est
donné) which is contrary to the most obvious experi-
ence. Equally false is radical indeterminism, which, in
positing creatio ex nihilo of each moment, ignores the
dynamic continuity of duration and thus makes both
memory and causation impossible. Mathematical
continuity (infinite divisibility) belongs only to the
spatial segment by which duration is inadequately
symbolized, not to duration itself. In other words, the
durationless present is a fiction not only in psychology,
but in physics as well; even the physical processes have
a fine pulsational structure, even though their temporal
span is enormously shorter than that of mental events
(Matter and Memory, Ch. IV). This view is also shared
by A. O. Lovejoy, although he insisted against Bergson
that the temporal segments must have sharp boundaries
if the genuine difference between the successive phases
should be preserved. Although critical of some aspects
of James's and Bergson's thought, Lovejoy shared with
them their temporalism—the term which he himself
coined for doctrines which took time as an essential
category of all existence.

Another outstanding temporalist or “process philos-
opher” is Alfred North Whitehead; his metaphysics of
events with its emphasis on “the creative advance of
nature,” “the immortality of the past” (from which the
irreversibility of Becoming follows), and the denial of
durationless instants was very close to the views of
James and Bergson. Besides acknowledging his affinity
with Bergson's views, Whitehead also stressed his debt
to Samuel Alexander's work Space, Time and Deity
(1920), and, to a lesser degree, to Lloyd Morgan and
C. D. Broad. Like Alexander, and also under the influ-
ence of the relativity theory, Whitehead stressed the
inseparability of space from time; but unlike Alex-
ander, Morgan, and Broad, Whitehead regarded, in the
later phase of his thought at least, his own concept
of novelty as incompatible with classical determinism.
Broad's original view about “the reality of the past
and the unreality of the future” was given up later
by his belief in precognition which requires the pre-
existence of the future in some form. John Dewey, who
was one of the first to welcome Peirce's rejection of
classical determinism (“The Superstition of Necessity,”
Monist, 3 [1893], 362-79), unlike other process philos-
ophers, did not regard the reality of all-pervasive
change as the source of cosmic optimism: “change is
nothing to gloat over—” (Experience and Nature,
Chicago [1925], p. 71). It is, however, fair to state that
the term “meliorism,” coined by William James, de-
scribes far more accurately than “optimism” the view
of the process philosophers mentioned. An even more
pessimistic view of time is that of Heidegger; his
connotation of becoming is completely divorced from
that of evolution and creativity; time is viewed only
in its tragic and destructive aspects.

The interest in the problem of time was not confined
to process philosophers only. Thus Josiah Royce used
the durational present as a model for understanding
the relation of time and eternity; the divine conscious-
ness, “Eternal Now,” is still temporal, although its
temporal span is incomparably wider than that of the
human specious present. Bertrand Russell, who favored
the concept of mathematical instants in his Principles
of Mathematics (1903), gave it up in his article “On
the Experience of Time” in Monist (25, 1915). Husserl's
phenomenological analysis of time in Die Phänomenol-
ogie des inner Zeitbewusstsein (1966) was in his own

view in many respects similar to the introspective
analysis of Bergson (cf. Roman Ingarden, “L'intuition
bergsonienne et le problème phénoménologique de la
constitution,” in “Bergson et nous,” Bulletin de la
Société Française de Philologie [1959], 165-66).

The development of physics in the twentieth century
profoundly modified the classical concepts, including
that of time. The theory of relativity proposed the
union of space with time; the significance of this union
is still being discussed. According to the widespread,
but very questionable view, it means an assimilation
of time to the fourth dimension of the static, becoming-
less continuum—“space-time.” Serious objections have
been raised against such interpretation not only by
philosophers like Meyerson, Bergson, and Reichenbach,
but also by scientists like Eddington, A. A. Robb, and
Whitrow. Occasionally Einstein himself stressed that
even within the relativistic “space-time” the time di-
mension is not equivalent to the spatial dimensions.
It is far more correct to speak of the dynamization
of space rather than of the spatialization of time; the
relativization of simultaneity means that “instanta-
neous space,” that is, the class of simultaneously exist-
ing events, cannot be unambiguously carved out of the
four-dimensional world-process. It is also significant
that while the succession of causally related events
remains a topological invariant within relativity phys-
ics—i.e., the world-lines remain irreversible in any
frame of reference—it is not so for the spatial distances;
thus the relativity of simultaneity can equally appro-
priately be called the relativity of justaposition. It has
been correctly pointed out that in the relativistic phys-
ics the past is separated from the future not by the
durationless three-dimensional “Now” spreading in-
stantaneously across the universe as in the physics of
Newton, but, even more effectively, by the four-
dimensional region of “Elsewhere.” It can also be
shown that an event which is in the causal future for
a certain observer cannot be in the causal past of any
conceivable observer. This follows from Minkowski's
formula for the invariance of the world interval:

I = s2 - c2(t2 - t1)2 = const.

s is spatial distance separating two events, (t2 - t1)
being their separation in time.

The most common source of the antitemporalistic
misinterpretations of the relativity theory is the confu-
sion of the metrical invariance with the topological
invariance of time; while the latter is preserved, the
former is not. This can be shown when we analyze
the popular relativistic paradoxes. Some of these
“paradoxes” are due to sheer ignorance; for instance,
under no circumstances can anybody or anything
“travel backwards to the past” as it follows immedi
ately from the relativistic space-time diagram. Even
the famous “paradox of twins,” first mentioned by Paul
Langevin in 1911, implies the metrical, not the topo-
logical relativity of temporal intervals; the twins aging
at different rates, both move in the direction of the
future and it is a misunderstanding to claim that one
can make an exploratory “round trip” to the future
and back.

Dynamization of space is even more conspicuous in
the general relativity theory which fuses the physical
content with the variable spatiotemporal continuum,
and thus challenges the classical container-like charac-
ter of absolute space and time. Thus time is inseparable
from concrete physical events in a sense much more
radical than the classical relational theory of time
suggested. Thus the gravitational and inertial field—
both being according to the principle of equivalence
two aspects of the same phenomenon—are not in
space-time; they are nothing but certain local irregu-
larities of space-time, and the changes in the local
curvature of space-time appear to us as the displace-
ments of bodies in the allegedly inert space. The reces-
sion of the galaxies which suggested the idea of the
expanding space shows how far modern cosmologies
are from the immutable space of Newton.

Significant changes of the concept of time are also
suggested by the quantum theory and wave mechanics.
The implications of these changes point in the same
direction as those of the relativity theories. The quan-
tum character of the microphysical processes makes
probable the view that physical time—like psycho-
logical time—is not divisible ad infinitum: that is, that
there are the minimum intervals of time which are not
further divisible since they coincide with the elemen-
tary events of nature. This is the meaning of “l'atome
du temps” of Poincaré, of “quantum of time” of
Whitehead, and of “chronon” of some contemporary
physicists. It is always possible to assume that under-
lying the temporally indivisible events of microphysics
there is the mathematical, infinitely divisible duration
of Newton and Locke; but this view implies the abso-
lutist distinction between homogeneous container-like
time and its concrete physical content, which the pres-
ent trends in physics make improbable. It is true that
for practical purposes, that is, on the macrophysical
level where the magnitude of Planck's constant h can
be disregarded, and where the interval of chronon is
practically equivalent to a mathematical instant, time
remains very approximately continuous. The chronon
theory would remove the distinction between physical,
infinitely divisible duration and psychological time—or
rather it would reduce this distinction to that of degree
only, the physical “chronons” being of incomparably
shorter temporal span than the temporal minima sen

sibilia in psychology. But since these temporal minima
cannot be conceived as sharply separated, a serious
difficulty arises as to how to synthesize conceptually
the individuality of events with the continuity of be-
coming. It is probable that without a radical modifica-
tion of our conceptual tools this will be impossible.
Such modification is suggested by some recent attempts
at constructing “topology without points” or “fuzzy
set theory.”

Another even more important philosophical conse-
quence of the existence of Planck's constant is the
indeterminacy of the microphysical processes, formu-
lated by Heisenberg (1927). The two different names
of this principle—“uncertainty principle” or “indeter-
minacy principle”—suggest two radically different
interpretations of it. The first interpretation, more
conservative in its outlook and favored more by tradi-
tionally oriented philosophers than by physicists, re-
gards microphysical indeterminacy as a result of the
interference of the process of observation with the
process observed. The second interpretation, more
favored by physicists, regards it as a manifestation of
objective indeterminacy in nature. The first inter-
pretation leaves the Laplacean determinism intact; the
second one suggests the objective status of chance in
the sense of Boutroux and Peirce, that is, of the “open
world” (H. Weyl's term), forever in growth and forever
incomplete, in which the future remains genuinely
ambiguous and, though influenced by the past, is not
predetermined by it. While the first interpretation is
more congruous with the philosophical tradition glori-
fying static and immutable Being, the second inter-
pretation is viewed with sympathy by the process-
oriented thinkers. Thus the discussion concerning the
interpretation of this principle is merely the most
recent phase of the ancient dialogue between Par-
menides and Heraclitus.

BIBLIOGRAPHY

For the history of the concept of time, Walter Gent, Die
Philosophie des Raumes und der Zeit, 2nd ed. (Hildesheim,
1962) is a very useful sourcebook. For the concept of time
in medieval cosmology see the relevant chapters in Pierre
Duhem, Le système du monde, Vols. I-X (Paris, 1913-59).
Z. Zawirski's L'évolution de la notion du temps (Krakow,
1934) includes the modifications of the concept of time in
recent physics. A very extensive bibliography of recent
English articles on time is in J. J. C. Smart, Problems of
Space and Time (New York, 1964) while The Voices of Time,
ed. J. T. Fraser (New York, 1965) is a cooperative volume
dealing with the historical, psychological, biological, and
physical aspects of time.

Modern restatement of the Eleatic denial of time are
F. H. Bradley, Appearance and Reality (London, 1893), Chs.
4, 18 and J. M. E. McTaggart, “The Unreality of Time,”
in Mind, N.S., 17 (1908), while Josiah Royce, in Lecture
3, The World and the Individual, Vol. II (New York, 1901),
tries to synthesize the temporalistic and eternalistic view.
Reaffirmation of the reality of temporal succession are:
Henri Bergson, Oeuvres complètes (Geneva, 1945); William
James, A Pluralistic Universe (New York, 1910); idem, Some
Problems of Philosophy (New York, 1911); Samuel Alexander,
Space, Time and Deity (London, 1920); A. N. Whitehead,
Process and Reality (Cambridge, 1929); Charles Hartshorne,
“Contingency and the New Era in Metaphysics,” Journal
of Philosophy, 29 (1932); Mary F. Cleugh, Time and Its
Importance in Western Thought (London, 1937); Paul Weiss,
Reality (Princeton, 1938); A. O. Lovejoy, Reason, the Un-
derstanding and Time (Baltimore, 1964); Philip P. Wiener,
“The Central Role of Time in Lovejoy's Philosophy,” Phi-
losophy and Phenomenological Research, 23 (1963).

On the physical status of time: H. Poincaré, “La mesure
du temps,” Dernières pensées (Paris, 1913); Einstein-
Lorentz-Minkowski-Weyl, The Principle of Relativity, trans.
W. Perret and G. B. Jeffrey (London, 1952); A. S. Eddington,
The Nature of the Physical World (Cambridge, 1928), Chs.
III-V; É. Meyerson, Identité et réalité, 5th ed. (Paris, 1951);
idem, La déduction relativiste (Paris, 1925), Ch. 7; A. A. Robb,
The Absolute Relations of Time and Space (Cambridge,
1921); H. Mehlberg, “Essai sur la théorie causale du temps,”
Studia philosophica (Leopolis [Lvov], 1935); H. Reichen-
bach, The Philosophy of Space and Time (New York, 1958);
idem, The Direction of Time (Los Angeles, 1956); A. Grün-
baum, Philosophical Problems of Space and Time (New York,
1964); M. Čapek, The Philosophical Impact of Contemporary
Physics (Princeton, 1961); G. J. Whitrow, The Natural Phi-
losophy of Time (London and Edinburgh, 1961); A. N. Prior,
Papers on Time and Sense (London, 1968); idem, Past, Pres-
ent and Future (London, 1967); idem, Time and Modality
(London and New York, 1957).

On the perception of time, see William James, Principles
of Psychology, Vol. I (New York, 1890), esp. Chs. 9, 15;
Bertrand Russell, “On the Experience of Time,” Monist, 25
(1915); Edmund Husserl, Die Phänomenologie des innern
Zeitbewusstsein, ed. R. Boehm (The Hague, 1966); Paul
Fraisse, Psychologie du temps (Paris, 1957) contains a very
complete bibliography.

MILIČ ČAPEK

[See also Atomism; Cosmic Images; Cycles; Determinism;
Evolutionism; God; Pragmatism; Pre-Platonic Concep-
tions; Pythagorean...; 2">Relativity; Skepticism; Space;
Uniformitarianism.]