Albertus Magnus Philosophia (1496 Incunable)

Physics

...the likeness of a point. For let us suppose, for the sake of an impossible argument, that there is a point flowing along a line: that point, by its own flow, continuously creates a successive line original: "lineam successiuam"; a line that comes into being through the progress of the point. which does not have matter in its parts—by which I mean a line that has no substance other than the substance of the point. However, it has a different way of being according to whether the point is "here" or "there" in length, or "before" and "after." The now—which is the substance of time—shares a likeness with that point. In this context, the "now" is not taken as a limit. But conversely, in a mathematical length, there is a point that acts as a limit; the "now" shares a likeness with that point insofar as it is the limit of time. However, it is not a limit in actual fact, but only in relation to the intellect or to some specific motion. If anyone wished to distinguish these according to Avicenna Ibn Sina (c. 980–1037), a Persian physician and philosopher whose commentaries on Aristotle were central to medieval European science., he would say: that the "now" which is the substance of time is properly called the instant original: "instans"; Avicenna uses a wordplay here—"instans" as if "non stans" (not standing still).. But the "now" which is the limit of time retains the proper name of the now itself.

It should be noted that the relationship of the point to the line and the "now" to time are similar in some ways, but different in others. For instance, in the way they act as a limit and a point of continuity, they are somewhat similar. However, in their "essentializing" (if I may call it that) or in their "substantiating," they do not relate similarly. This is because a point does not "make" a line—neither a flowing point nor a stationary one—but the now, by its own flow, "makes" time, as has been said. Therefore, the point is not the substance of the line.

It was said that the "now" and the point are somewhat similar in limiting and continuing, because in a line one can perceive two limits in actual fact. But Avicenna proves that the "now" is not a limit in time in actual fact, because there is no interruption of time according to its own nature, but only according to the intellect, or according to a comparison to some determined motion. Similarly, a connecting point is both a beginning and an end; therefore, whoever uses a connecting point uses the same thing twice. Because of this, rest original: "quiescere"; the state of being at rest or not moving. happens. That is to say, if a motion occurs upon a line such that a moving object "uses" a connecting point, it uses it as the end of the preceding magnitude; and thus it will use it in the state of "having moved" rather than "moving," since motion does not exist at the exact end-point of any magnitude, as is proven in the sixth book of the Physics.

But if one uses it as a beginning, then one uses it as the first thing after which there is motion in the following magnitude. But whenever one uses a point, one uses it as a "now." If one uses the point twice, one uses it in two "nows"; and between any two "nows" there is a middle time. Therefore, between the "now" in which one uses a point as an end, and the "now" in which one uses that same point as a beginning, there is a middle time—and in that time there is rest. This is what the Philosopher A standard medieval reference to Aristotle. says in the fourth book of the Physics: when a moving object uses one point as if it were two, rest occurs. There is, therefore, a dissimilarity: a connecting point in a line is easily taken as a beginning and an end such that nothing exists in between; but the "now" can never be taken as a beginning and an end unless a middle time falls between them.

And it should be noted that substance is spoken of in one way as something being what it was; and in this way, the "now" is not the substance of time, being indivisible...

b