ARISTOTLE ON TIME
INTRODUCTION
Time remains one of the most
mysterious aspects of the universe that seems to elude definitiveness. As St.
Augustine will say when asked of time: “if no one asks it of me, I know, but if
I wish to explain it to him who asks me, I know not”. The beginning of
civilization on earth required knowledge of the length of days, months, and
seasons, since it commonly surround production of goods, especially growing of
crops. The development of time began with natural time-keeping i.e. observing the
moment of the sun, and moon, as well as seasonal changes such as rainfall,
harmattan, spring, etc leading to the development of the water glass, hourglass
and culminating in the first mechanical clock produced in China. Over the cause
of man’s existence, philosophers have tirelessly sought for clearer understanding
of the concept of time. Some have argued that time is a basic component of the world;
while others claim it is an illusion and a composition of the human mind, thus
not part of the real world.
Aristotle in his book “physics”, apart from presenting us with
an insight to the theory of time, gives us an idea of the general belief of
time in his period in history. His approach to this topic is less rhetorical,
and easy to understand, because he treats time with as it appears to the common
man. When he asks himself what time is, he inquires in himself what the common
man on the street thinks of time, and not what the likes of Homer, or
Pythagoras thinks.
DOES TIME
EXIST?
In order to understand time, we must
first ascertain its existence in our reality. Aristotle lays the question of
the existence of time to lie with two definitive statements. First he says,
* “one part of it has been and is not, while the other is going to be and
is not yet”[1]
This implies that time is composed of
what has been, and what will be, both of which do not exist. The former called
“before” and the later called “after” is not anything, lacking the substance,
thus doesn’t share in reality.
Then, he continues,
* “If a divisible thing is to exist, it is necessary that when it exists,
some or all its parts must exist”[2]
This requirement too, time fails to
meet, for some of its parts are already past, while others are yet to be, and
the only seemingly actual aspect of it called “now” is passing away and cannot
be held unto, coupled with the fact that it is not a part of time. The “now” not
being part of time gives impetus to the first definitive statement about time.
Therefore, time though useful in reality, is not part of it.
NATURE OF
TIME
In Aristotle’s period it was a common
belief that time is revolution, since the day revolve
(morning-night-morning-night-…..), just as seasons revolve. Aristotle debunks
this claim asserting that time though part of revolution is not revolution in
itself, just as motion is a part of movement of an object, but not part of the
object. He continues by saying that if there were many heavens that undergo
revolution, than there will be many times according to the number of heavens,
which is not obtainable, running contrary to his conception of absoluteness of
time.
Aristotle therefore defines time as:
“Motion or
movement according to the prior (before) or posterior (after).”
This definition unequivocally ties
time to motion. Thus, for there to be time, there must be motion. This does not
suppose that without motion time will not exist, rather time is a measure of
motion. This is made clear if we consider the fact that time is steady, or
determinate, but motion may be fast or slow. Also, even when the senses are put
to rest, and the mind alone is active (such as imagining, or dreaming), it (the
mind) can still detect a lapse of time between when is left the world of the
sense and its return. This is because even when in this state, the mind is
undergoing changes in its own reality, just as the sensual parts are also doing
same even though the mind fails to perceive it. It therefore follows that time
depends upon perception of changes or motion by the mind, thus events are not
measured in time except through the medium of the mind, giving time its true
nature: a conception of the mind rather
than a property of the cosmos. This view is contrary to Plato’s claim in
the Timaeus that time was created by
God, as the moving image of eternity, when he ordered the cosmos. For Plato,
time is a part of the universe.
Aristotle doesn’t fail to acknowledge
the existence of things that are “always” (he may be referring to the souls or Plato’s
world of ideas), things that don’t undergo change, or corruption, or
degradation, and their relation to time. In respect to these realities he says:
“Not
in time, not affected by time, not contained in time, and their essence not
measureable with time.”
In contrast to this, corporeal things
exist in time and their essence measured in time. However, this doesn’t mean
that corporeal things co-exist with time, for if they do, all things will live
infinitely, and all things will possess the ability to become any other thing.
Another characteristic of nature is
that it is number. Since time is a measure of motion, then it is enumerable, if
enumerable, if so then it is a number, which can be divided. Consequently if
time is number, and numbers can be either countable, and infinity in quantity,
then infinity time can also be found (he may be referring to eternity).
CRITICISM OF
ARISTOTLE’S CONCEPT OF TIME
Crescas criticizes Aristotle’s
definition of time as a measure of movement, redefining it as duration of
motion or rest between two instants. He argues that linking time directly with
motion trivializes or negates in complete independence on motion. For Crescas,
duration is the continuity and flow of the activity of a thinking mind, be it
God or a mortal soul. Therefore, given a thinking mind, even when there is no
external reality, there would still be duration, and time will continue to exist.
I think Crescas, pushes this point far beyond this universe, placing even God
within the boundaries of time, which negates the eternity of God, and the Divine
milieu. It also doesn’t tell us the origin of time, or that time started with
the origin of a thinking mind, which this case may be God.
Aristotle’s absoluteness of time is
on theory that has undergone series of transformation. Newton, a seventeenth
century physicist, in his theory of motion supports Aristotle’s absoluteness of
time. Newton asserts that the speed of light would vary according to the
position of source and observer. This means that different observers will view
the occurrence of an event at the same time irrespective of their position
within the universe. However, in the twentieth century, Einstein brought about
dramatic twist to this long held theory with his theory of relativity, which
holds that the constancy of the speed of light is irrespective of distance. The
implication is that one cannot speak of an event happening at a precise time
for different observers. For each observer, the time frame (space-time) is
relative to his/her location. For instance, when two astronomers are observing
an event within the earth’s milieu, one on earth and the other on Saturn, the
astronomer on earth will via his telescope see the event at the time of
occurrence, whereas the astronomer on Saturn will see it seventy five minutes
later, which to him is the time of occurrence of the event. This theory of
relativity of time is a novelty in the field of physics, which upholds time,
being an empirical field of study.
CONCLUSION
In establishing a firm relationship
between time and motion, Aristotle presents an essential attribute of time in
fulfilling its major responsibility. These responsibilities of time include:
1. To place events in
sequence, one after another
2. To evaluate and compare
how long events lasts
3. To tell when an event
occurs.
Unlike the likes of Zeno who holds
that time is nonexistent, since everything is constant i.e. no change is
occurring, Aristotle, makes clear that changes occur in nature, and that they
follow a pace particular the nature the substance undergoing change.
BIBLIOGRAPHY.
1. Aristotle, Physics. Transl. by W. D Ross.
Clarendon, London: Oxford University Press, 1930.
2. Arthur Fine, “Einstein
Albert”, The Encyclopedia of Philosophy vol. 3, ed. Donald M. Borchert, (2006)
ed., p. 178
3. Geoarge S. F. An
Introduction to Philosophy, London. Macmillian and co. ltd, 2005.
4. Harry Austryn Wolfson. Crescas Critique of Aristotle. Philadelphia,
PA, U. S. A. The Jewish Publication Society Press, 1929.
5. Vincent Edward Smith. The
General Science of Nature, U. S. A. The Bruce Publishing Company, 1958.
6. William L. Harper, “Newton
Isaac”, the Encyclopedia of Philosophy vol. 6, ed. Donald M. Borchert, (2006)
ed., p. 590.
7. Philip stokes. 100
Essential Thinkers”, NY. Enchanted Lion Books, 2006.
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