Let us divide the answer in three parts: 1) Differentiation between pheronomical and dynamical, 2) Exploration of this text and 3) Problematization of the pheronomical differentiation.
(Khan Academy - Introduction to reference frames - Referential is irrelevant for the velocity - Pheronomical observer)
1) Differentiation between pheronomical and dynamical
Dynamics has exactly the same meaning as it would have in a Newtonian context, that is, it is the behavior of bodies subjected to forces, which accelerate them, given that F=ma, as actually could be the definition of force.
Pheronomical is the junction of φέρω (phero) that means "to mantain", "to carry", "to bear", and νόμος (nomos) that means "rule", "law", "human determination". Kant used this word to refer to a simple inertial movement, as Galileu Galilei posed.
(Inertial Forces in an Earthquake: acceleration of the referential causes change - Dynamical Observer)
In discussing the nature of motion, Kant distinguishes between its phoronomical and dynamical aspects, emphasizing the difference between subjective and objective interpretations.
Phoronomically, or in terms of pure mathematics and kinematics, motion is subjective because it is understood through the relative positions and changes of objects as perceived by the subject. In this context, motion does not imply any interaction or causation; it is merely a description of how positions change over time within the frame of reference of an observer. This is purely a matter of the observer's perspective and does not necessitate any external forces or causes.
Dynamically, however, motion is objective because it involves forces and interactions that exist independently of the observer's perspective. In dynamics, motion is explained through the application of physical laws and forces, such as Newton's laws of motion, which are considered objective because they describe interactions that can be universally applied and tested. These forces cause changes in motion and are considered to exist objectively, regardless of whether there is an observer to witness them.
Thus, when Kant says that motion is phoronomically subjective but dynamically objective, highlighting that the description of motion (phoronomy) depends on the observer's point of view and is therefore subjective. In contrast, the explanation of motion through forces (dynamics) is independent of the observer and is considered objective because it is based on universal laws of nature.
Let us see how this works in the context of the text.
2) Exploration of the Original Passage
"In logic the either-or always signifies a disjunctive judgment, where, if the one is true, the other must be false. For example, a body is either moved or not moved, that is, at rest. For here [in logic] one speaks solely of the relation of the cognition to the object. In the doctrine of appearance, where it is a matter of the relation to the subject, so as to determine the relation to the object therefrom, the situation is different. For here the proposition that the body is either moved and the space at rest, or conversely, is not a disjunctive proposition in an objective relation, but only in a subjective one, and the two judgments contained therein are valid alternatively. In precisely the same phenomenology, where the motion is considered, not merely phoronomically, but rather dynamically, the disjunctive proposition is instead to be taken in an objective meaning; that is, I cannot assume, in place of the rotation of a body, a state of rest of the latter and the opposite motion of the space instead."
Breakdown:
a. Logical Either-Or (Disjunctive Judgment):
- Explanation: In logic, an "either-or" statement is a disjunctive judgment, meaning that if one part of the statement is true, the other must be false.
- Example: "A body is either moved or not moved, that is, at rest." This means that if a body is moved, it cannot be at rest, and if it is at rest, it cannot be moved.
- Relation: This deals with how cognition (understanding) relates directly to the object itself.
b. Doctrine of Appearance:
- Explanation: When considering appearances (phenomena), we deal with how things appear to the subject (observer) and how this determines the relation to the object.
- Subjective Relation: The statement "the body is either moved and the space at rest, or conversely" is not an objective disjunctive proposition but a subjective one.
- Alternative Validity: Both judgments (body moved and space at rest, or body at rest and space moved) are valid from a subjective perspective, meaning either can appear true depending on the observer's point of view.
c. Phenomenology and Dynamics:
- Phenomenological Consideration: When considering motion not just phoronomically (describing motion mathematically) but dynamically (considering forces and interactions), the situation changes.
- Objective Meaning in Dynamics: The disjunctive proposition must be understood objectively. In dynamics, you cannot simply substitute the state of motion of one body with the opposite motion of the surrounding space.
- Example: "I cannot assume, in place of the rotation of a body, a state of rest of the latter and the opposite motion of the space instead." This means that if a body is rotating, you cannot just say that the body is at rest and the space around it is rotating to explain the motion; the forces and interactions that cause the rotation must be considered objectively.
3) Problematizaton (Pos Kantian)
We know what Kant means. Velocity is relative to the observer, but acceleration is always apparent, causing effects in the velocity, so we can understand it as absolute, dynamic.
Thus, there is no privileged reference for a phoronomical movement, every reference has speed in relation to others. The point is that there is no frame of reference that does not offer us inertial forces as well, as no frame of reference is immune to rotations, whether along with the rotation of the Earth, in the Sun's orbit, or with the Sun in its orbit in the galaxy or even from movements of the galaxy itself. Kierkegaard would likely resonate with the passage's notion that certain propositions are subjectively valid. He believes that existential choices are subjective and personal, reflecting the individual's internal struggle and perspective. See (Either-or, Soren Kierkegaard)
Impact of Inertial Forces in a Earthquake
