Argument#8
Statement No. 8
Force types and the stone-on-a-rope example
Explanations and summaries are editorial material. Consult the source to verify the original wording.
Faithful reading
Imam Ahmad Raza (rahmatullahi alayh) begins by dividing the kinds of coercive effects being discussed into two main classes. One is the mover, the cause that produces motion. The other is the resister or restrainer, which prevents the motion from increasing; for example, a hand can stop a stone that is slipping. He then divides the mover into two kinds. The first is attraction, which brings a moving body toward the side of the agent acting on it. The second is a force that throws the body in another direction; in the terminology of this statement, this is called repulsion.
To illustrate the distinction, he asks the reader to take A as the position of a man and C as the position of a stone. The man strikes the stone with a stick so that it moves from C to B. He says this is not attraction, because attraction would have brought the stone along the direction C–A, whereas the struck stone goes along C–B. Yet at B the stone is nearer to the man at A than it was at C, because AB is the perpendicular side while AC is the hypotenuse, and AB is shorter than AC. Thus, in this classification, becoming nearer does not by itself make the action attraction; the direction in which the body is driven also matters.
The statement then continues its classification of these effects. It speaks of a repulsive action that can keep a moving body at a particular height: for example, one may draw a stone toward oneself while keeping it just above the ground, or push it forward. It also distinguishes positive and negative forms and asks whether the body is taken away from, or brought toward, its destination. Another distinction concerns whether the line of motion remains the same or is changed.
The kind that changes the line of motion is called translatory in the source. In the second figure, a stone is thrown from A toward C. When it reaches B, it is struck with a stick and directed toward E; the source calls this translatory reflection or repulsion. When the stone reaches D and is pulled toward R, the source calls that translatory attraction. If the body is driven along the same line toward C and then pulled back toward A through B, the outward part up to B is called a positive resister, while the return from B is called positive attraction because it brings the body back along the same line.
Imam Ahmad Raza (rahmatullahi alayh) says that these divisions make thirteen types in all. He then applies the classification to the familiar example of a stone tied to a rope and revolved around the head. In this example, he says attraction has no role, because the purpose is not to draw the stone toward the person but to restrain it. From the remaining classes he identifies four working roles: the resister or restrainer, and three kinds he calls prohibitory, lifter, and translatory.
The prohibitory role is represented by throwing the stone outward far enough for the rope to become fully tight. The lifter is represented by keeping the hand raised so that the stone does not fall to the ground. The translatory role is represented by continually moving the hand around the head so that the stone's line of motion keeps changing. At the same time, the source assigns to repulsion the role of continually giving the stone a straight-line direction.
The statement says that at every point where the direction is changed, the stone would again take that straight direction, but the tightened rope, the lifting support, and the continual change of direction prevent it from simply going ahead. Their combined action confines the stone to a circular path. The man remains at the same distance from the stone and therefore serves as the center, while the rope performs the work of the restrainer.
The conclusion of the statement is that this stone-and-rope example should not be described as attraction. Imam Ahmad Raza (rahmatullahi alayh) says there is no inherent attraction or repulsion in the stone in this example; rather, the observable effect is produced by the restraint and by the applied action. He argues that the apparent power by which the stone seems to go away is being inferred from the resisting action applied while revolving it. He finally warns that the terminology is ambiguous when people speak of this as “repulsion toward the center of the circle” while elsewhere treating repulsion as being away from the sun, which they also take as the center.
To illustrate the distinction, he asks the reader to take A as the position of a man and C as the position of a stone. The man strikes the stone with a stick so that it moves from C to B. He says this is not attraction, because attraction would have brought the stone along the direction C–A, whereas the struck stone goes along C–B. Yet at B the stone is nearer to the man at A than it was at C, because AB is the perpendicular side while AC is the hypotenuse, and AB is shorter than AC. Thus, in this classification, becoming nearer does not by itself make the action attraction; the direction in which the body is driven also matters.
The statement then continues its classification of these effects. It speaks of a repulsive action that can keep a moving body at a particular height: for example, one may draw a stone toward oneself while keeping it just above the ground, or push it forward. It also distinguishes positive and negative forms and asks whether the body is taken away from, or brought toward, its destination. Another distinction concerns whether the line of motion remains the same or is changed.
The kind that changes the line of motion is called translatory in the source. In the second figure, a stone is thrown from A toward C. When it reaches B, it is struck with a stick and directed toward E; the source calls this translatory reflection or repulsion. When the stone reaches D and is pulled toward R, the source calls that translatory attraction. If the body is driven along the same line toward C and then pulled back toward A through B, the outward part up to B is called a positive resister, while the return from B is called positive attraction because it brings the body back along the same line.
Imam Ahmad Raza (rahmatullahi alayh) says that these divisions make thirteen types in all. He then applies the classification to the familiar example of a stone tied to a rope and revolved around the head. In this example, he says attraction has no role, because the purpose is not to draw the stone toward the person but to restrain it. From the remaining classes he identifies four working roles: the resister or restrainer, and three kinds he calls prohibitory, lifter, and translatory.
The prohibitory role is represented by throwing the stone outward far enough for the rope to become fully tight. The lifter is represented by keeping the hand raised so that the stone does not fall to the ground. The translatory role is represented by continually moving the hand around the head so that the stone's line of motion keeps changing. At the same time, the source assigns to repulsion the role of continually giving the stone a straight-line direction.
The statement says that at every point where the direction is changed, the stone would again take that straight direction, but the tightened rope, the lifting support, and the continual change of direction prevent it from simply going ahead. Their combined action confines the stone to a circular path. The man remains at the same distance from the stone and therefore serves as the center, while the rope performs the work of the restrainer.
The conclusion of the statement is that this stone-and-rope example should not be described as attraction. Imam Ahmad Raza (rahmatullahi alayh) says there is no inherent attraction or repulsion in the stone in this example; rather, the observable effect is produced by the restraint and by the applied action. He argues that the apparent power by which the stone seems to go away is being inferred from the resisting action applied while revolving it. He finally warns that the terminology is ambiguous when people speak of this as “repulsion toward the center of the circle” while elsewhere treating repulsion as being away from the sun, which they also take as the center.
Easy explanation
This statement is mainly a classification exercise. Imam Ahmad Raza (rahmatullahi alayh) is trying to separate several different ways in which a moving body can be pushed, pulled, stopped, supported, or turned. The labels belong to the argument of this book, so the easiest way to read the section is to first understand what job each label is doing.
The first split is simple. A mover makes motion happen or changes it. A restrainer limits that motion. If a stone is sliding and your hand stops it, your hand is doing the restraining job. This gives the statement two broad roles before it begins making smaller divisions.
Next comes the difference between and what the source calls . Here, attraction means bringing the moving body toward the acting agent. Repulsion means driving it in another direction. The important point in the source is that the name depends not only on whether the body becomes nearer or farther away, but also on the .
The first diagram explains this. A is the man's position and C is the stone's starting position. A strike sends the stone from C to B. B is actually nearer to A than C is, but the stone did not travel along C–A. In the diagram, AB is the shorter side and AC is the . So the source says that the stone can become nearer to the man without the action being called attraction in its own classification.
The statement then adds more distinctions. It asks whether an action keeps the body at a certain height, moves it away from a destination or toward it, and whether the same line of motion is kept or changed. These divisions may sound complicated, but they are all trying to answer one practical question: exactly what change did the applied make to the body's motion?
The second diagram is about a change of direction. A stone first moves from A toward C. At B it is struck and turned toward E; the source gives that change one label. Later, at D, if the stone is pulled toward R, the source gives that a different label. The same idea is then applied to motion along one line: going away along the line and coming back along that same line are placed in different categories.
After completing this classification, the statement turns to the stone tied to a rope and swung around the head. It says that four jobs are visible there. The rope keeps the stone from escaping farther outward. The raised hand keeps it from falling. The moving hand keeps changing its direction. And the source assigns a straight-line tendency to the repulsive role.
That last point is central to the example. At any instant, the stone has a direction in which it would continue if nothing kept turning it. The source describes that as a that reappears at each new point. The rope and the changing direction prevent the stone from simply continuing along that straight path.
Because the rope stays tight and the hand keeps turning, the stone follows a instead. The person remains at the of that circle, at roughly the same distance from the stone. In the source's language, the rope is therefore acting as the restrainer: it limits how far the stone can go from the center while its direction keeps changing.
This leads to the main claim of Statement 8. Imam Ahmad Raza (rahmatullahi alayh) says the stone-and-rope example does not require an attraction that pulls the stone toward the person. He also denies that the stone itself contains an independent outward repulsion in this example. In his reading, the apparent outward effect is connected with the restraint and with the way the stone is being driven and turned.
A simple modern picture can help with the geometry without changing what the source is arguing: a body moving around a circle is continually changing its direction, and if the constraint disappears, its immediate continuation is along the current straight direction. Statement 8 uses its own older vocabulary for these roles and then warns that words such as “repulsion” can become confusing if they are used with different meanings for the circle and for the sun. That warning prepares the vocabulary for the next part of the book, but Statement 8 itself ends with this classification and the stone-on-a-rope example.
The first split is simple. A mover makes motion happen or changes it. A restrainer limits that motion. If a stone is sliding and your hand stops it, your hand is doing the restraining job. This gives the statement two broad roles before it begins making smaller divisions.
Next comes the difference between and what the source calls . Here, attraction means bringing the moving body toward the acting agent. Repulsion means driving it in another direction. The important point in the source is that the name depends not only on whether the body becomes nearer or farther away, but also on the .
The first diagram explains this. A is the man's position and C is the stone's starting position. A strike sends the stone from C to B. B is actually nearer to A than C is, but the stone did not travel along C–A. In the diagram, AB is the shorter side and AC is the . So the source says that the stone can become nearer to the man without the action being called attraction in its own classification.
The statement then adds more distinctions. It asks whether an action keeps the body at a certain height, moves it away from a destination or toward it, and whether the same line of motion is kept or changed. These divisions may sound complicated, but they are all trying to answer one practical question: exactly what change did the applied make to the body's motion?
The second diagram is about a change of direction. A stone first moves from A toward C. At B it is struck and turned toward E; the source gives that change one label. Later, at D, if the stone is pulled toward R, the source gives that a different label. The same idea is then applied to motion along one line: going away along the line and coming back along that same line are placed in different categories.
After completing this classification, the statement turns to the stone tied to a rope and swung around the head. It says that four jobs are visible there. The rope keeps the stone from escaping farther outward. The raised hand keeps it from falling. The moving hand keeps changing its direction. And the source assigns a straight-line tendency to the repulsive role.
That last point is central to the example. At any instant, the stone has a direction in which it would continue if nothing kept turning it. The source describes that as a that reappears at each new point. The rope and the changing direction prevent the stone from simply continuing along that straight path.
Because the rope stays tight and the hand keeps turning, the stone follows a instead. The person remains at the of that circle, at roughly the same distance from the stone. In the source's language, the rope is therefore acting as the restrainer: it limits how far the stone can go from the center while its direction keeps changing.
This leads to the main claim of Statement 8. Imam Ahmad Raza (rahmatullahi alayh) says the stone-and-rope example does not require an attraction that pulls the stone toward the person. He also denies that the stone itself contains an independent outward repulsion in this example. In his reading, the apparent outward effect is connected with the restraint and with the way the stone is being driven and turned.
A simple modern picture can help with the geometry without changing what the source is arguing: a body moving around a circle is continually changing its direction, and if the constraint disappears, its immediate continuation is along the current straight direction. Statement 8 uses its own older vocabulary for these roles and then warns that words such as “repulsion” can become confusing if they are used with different meanings for the circle and for the sun. That warning prepares the vocabulary for the next part of the book, but Statement 8 itself ends with this classification and the stone-on-a-rope example.
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