Of course a line wouldn’t perfectly model time, they are two different things, but I think the parallels are legitimate especially in the context of Individuals and our perception of time.
Plato:
To get back to your point that time is analogical to a line. It might be useful to say that, “Time is to a Line as the Now is to a Point.” Except, unlike the line,
time exists only successively. It never exists with all of its parts simultaneous with one another. A line, on the other hand, can exist with all of its parts in simultaneity. Thus, there is a difference between time and anything merely geometrical.
As you correctly point out, the
now (or instant) is like a point on a line. Typically, one side of the line represents the past, while the other represents the future. Of course, we are still quite vague as to what exactly the
now is, but, it seems to be that which separates past from future. And, we certainly have reason to ask whether the
now is truly a part of time.
There is a big difference between the point on a line and the
now. Unlike the point on a line, the
now is always flowing. If we consider the point on a line undergoing imaginary motion, it would be regarded, from one position to the next, as the same point that was being moved. But, to the extent that the point is in some sort of motion, the point would always be different. As St. Thomas says, " It would be the same subject with constantly changing relations." (
Summa Theologica, Book I, q. 10, a. 4, reply 2)
So too, with the
now. As the
now flows, it does not go out of existence in the past only to come back into existence in the future. Time is like the line generated by the moving point of our imagination, and the
now is like the point itself. Time, then, is generated by the
now flowing. If we consider this, we come to understand that the
now has a continuous existence, as it flows through time, but, as always flowing, this existence must always be different.
If we can understand the
now as always flowing, as described above, we will have no problem understanding why it can unite the past with the future, in a continuous flow, yet still leave them differentiated. The
now is like a moving point, and time is like a line. If we will think of the relationship between the
now and time in the same way that we understand a mobile being and motion, we can easily see that a mobile being, as it moves, leaves something of itself that is constant. For, even though the forward part of a mobile being is continuously moving forward, there is always a posterior part that remains behind, as it were, and is thus
constant. On the other hand, the forward part of the
now, like that of a mobile being, does not remain behind.
The
now, then, has a twofold character. The now is the
end (term) of the past and the
beginning (principle) of the future. We best grasp this as we ourselves take a step or two forward. Our noses move into the future while the backs of our heads have yet to leave the past.
Any intelligent disagreement here so far?
jd
