On Physics

...rare. And a house is a common place for all things that are in the house. A proper place In Aristotelian physics, a 'proper place' is the specific, immediate boundary that surrounds a single object, as opposed to a 'common place' like a room or a city. is the circumscription of a body enclosing a thing: it is neither larger nor smaller than the body which it encloses; and according to this, it is a quantity.

On Time. Chapter 12.

Next follows the subject of time, concerning which: First, it must be said what it is. Second, what it means to be in time. Third, regarding the differences of time. Fourth, regarding the distinction of time.

Time is defined thus by Aristotle original: "Aris." in the fourth book of the Physics: Time is the number of motion according to the before and the after. Likewise: Time is the measure of motion according to the before and the after. These definitions are more clearly understood by comparing time to local motion Motion from one place to another., of which time is the first and most essential attribute original: "propria passio"; literally a 'proper passion,' meaning a necessary characteristic that follows from the nature of the thing..

Therefore, local motion occurs over a magnitude In this context, magnitude refers to the physical distance or extension over which an object moves. which has a part "before" and a part "after"; and those two parts are described in respect to some middle part. However, the mobile object The thing being moved. that is moved over it is also divisible; it exists in a state of potentiality for the renewal of its "where," its place, and its position. This divisible potential corresponds to the parts of the magnitude, the "where," the place, and the position. Since this potential is itself divisible, and since for every divisible thing there must be a measure, there will be some measure of that potential as it moves into actuality The transition from 'potential' (being able to move) to 'act' (the state of moving)..

The thing that is carried or moved in its motion is one and the same being. Yet, it maintains a relationship to the parts of the magnitude with respect to the starting point original: "termini a quo" and the ending point original: "termini ad quem" toward which the motion proceeds continuously. Since, therefore, motion is the medium between the magnitude (the distance) and the measure of that motion, the measure of potentiality passing into actuality continuously during motion will have three effects caused by that potential:
1. The before and after, caused by the before and after points in the motion.
2. The middle connecting them, which corresponds to the object being carried or moved continuously from the starting point to the ending point.

Thus it is clear that motion is continuous because of the continuity of the magnitude, or the space over which the motion occurs. In motion, there is a before, an after, and a middle; but this "middle" is not the same as the moving object itself, just as in magnitude or position, the middle point is not always the same between any two parts chosen as "before" and "after" in the whole distance.

Just as the object that moves continuously through the whole distance is the same in its substance Its essential identity as an object., yet it does not have the same way of being as it flows from the "before" to the "after"—which flow it gains from the continuous progress of the mobile object from the earlier part to the further part of the distance—even though the substance remains the same throughout the continuous motion.

And thus it is clear that the Now original: "nunc"; the instant or the present moment. is the substance of time, because time is nothing other than the "now" receiving continuous being through its own flow. For nothing can be grasped of time except the "now." For that which has passed does not exist; similarly, that which is future does not yet exist. Having seen these things, it must be known that there are two kinds of number: namely, the numbering number...