In this blog post, we will examine how process theory, as proposed by Salmon, can explain causality and what its limitations are.
Since the modern era, Western philosophers have tended to limit causality to physical interactions, unlike in the past, with the emergence of a scientific worldview. In this process, philosophers began to emphasize scientific methodology and empirical evidence. The problem, as Hume pointed out, is that causality itself cannot be directly observed. We can only observe events that correspond to causes and effects. For example, “The river froze because it was cold” is not a statement of directly observed physical facts. Hume’s skepticism questioned the impossibility of observing such causal connections. This raised doubts among philosophers as to whether causality was a scientific concept.
Samen’s process theory is an attempt to understand causality based on a scientific worldview. Samen sought to overcome the limitations of traditional causal explanations. When you throw a baseball, its shadow on the ground also moves. It is the ball that moves, causing the shadow to move, not the shadow itself that moves and changes its position. Process theory explains this difference as follows. A process is the spatiotemporal trajectory of an object. Not only a flying baseball, but also a ball resting on the ground traces a spatiotemporal trajectory because time is passing. Even when the ball is stationary, it is still a process. However, not all processes are causal processes. Some processes meet other processes at a point in space and time. In other words, two processes intersect. If a sign, or a changed physical property of an object, is introduced at the intersection, then the process that transmits that sign at all subsequent points is a causal process.
For example, let’s say that the process of a banana moving from point a to point b is process 1. At the midpoint between a and b, process 2, which is the process of taking a bite out of the banana, intersects with process 1. At this intersection, a sign is introduced into process 1, and this sign can be transmitted to b. In other words, the banana can move to b with the amount that was bitten out remaining missing. Therefore, process 1 is a causal process. The movement of the banana is the cause of the banana being located at b. On the other hand, suppose that the shadow of the banana appears on the screen. Let’s call the process of the banana’s shadow moving from point a′ to point b′ on the screen process 3. After the intersection of processes 1 and 2, the shadow on the screen also changes. However, suppose that process 4, in which bumpy styrofoam is attached to a point on the screen surface between a′ and b′, intersects with process 3. When the shadow overlaps that point, a sign of distortion is introduced into process 3, but once the shadow passes that point, it returns to its original state and the styrofoam remains unchanged. Thus, process 3 cannot convey signs introduced by intersections with other processes.
Process theory has limitations in that it is difficult to explain aspects outside the physical world, such as norms and the mind. For example, there is a causal relationship between my violation of social norms and my punishment, but process theory cannot handle this well. To overcome these limitations, some philosophers began to seek new approaches to complement causal explanations. They attempted to understand causal relationships on a different level from physical processes and proposed complex causal models that took social and psychological factors into account. This is considered an important attempt to expand the scope of causal understanding.
