In this blog post, we will philosophically examine whether the true cause of a causal relationship is an event or an agent with free will, focusing on Reid’s agent causal theory.
Suppose that a red ball collides with a stationary white ball, causing the white ball to move. Hume identified three conditions necessary for a causal relationship to exist between the event of the red ball colliding with the white ball and the event of the white ball moving. First, the cause must precede the effect in time. Second, the cause and effect must be spatially connected. Third, there must be a “permanent connection” between the cause and the effect. A constant conjunction means that if balls move in the same way under similar circumstances, they will collide in the same way. However, Reid argued that even if Hume’s three conditions are met, as in the above example, a causal relationship does not exist. He believed that only an agent with free will can be a cause.
In the agent causal theory, Reid defined the cause as an entity that possesses “dual capacity” and is responsible for its change. Dual capacity is the active ability to produce or not produce change. An agent is an entity that possesses the ability to produce a result, can exercise that ability, and is responsible for the change. Leed argues that the true cause is the agent. According to this view, when a red ball collides with a white ball, the white ball can only move and cannot remain stationary, so the red ball cannot be the agent.
Leed also emphasized empirical evidence for causal relationships. In his view, causal relationships must be based on actual experience, not mere logical inference. For example, if we conduct repeated experiments and always obtain the same results under specific conditions, only then can we be certain of a causal relationship. However, such empirical evidence can be understood in a different dimension from the free will of the agent, as free will is an internal decision that cannot be observed empirically.
From the perspective of the empiricist Reid, the only agent within the scope of observation is humans. If a person rolls a red ball to move a white ball and the white ball moves, then the person is the agent and the movement of the white ball is the result. Reid believed that for a result to occur, the agent must exercise a dual capacity, and the agent’s desire must always be combined with it. Reid viewed desire as an event that occurs in the mind. In this regard, it could be argued that the desire combined with the exercise of the two-sided ability that produced the result manifests itself as the exercise of another two-sided ability, which in turn requires another desire. In response to this argument, Reed held that intrinsic mental activities such as desire cannot be distinguished from the exercise of the agent’s two-sided ability, i.e., “arousing desire,” and the desire itself as its result. This means that in the case of arousing motivation, the act of exercising the agent’s ability is itself motivation, so no further motivation is required.
Leed also engaged in a deep discussion of human moral responsibility. He argued that the reason humans can be held responsible for their actions is precisely because they have free will. This free will enables humans to decide their own actions and thus makes them morally responsible for the consequences of those actions.
This emphasizes that human actions must be understood in a moral and ethical context, beyond simple physical causality. However, Reid’s view that motivation and events are always combined can be countered by the argument that the cause of an event is not the actor but the motivation. In response, Reid supported his theory with the argument that constant combination alone cannot justify the necessity of causality. While emphasizing the role of desire, Reid argued that the mere existence of desire is not sufficient. He maintained that a causal relationship is established only through the process by which desire manifests itself as an action and that action brings about a result. Reid also had to address the issue of “occasional causes.” At the time, influenced by medieval philosophy, some philosophers believed that the true cause of events, including human actions, was God alone, and that actors were merely occasional causes.
Opportunity causes appear to be causes in everyday life, but they are not true causes. Reid rejected this position from an empiricist perspective. He argued that we can only experience the agent’s desire and action, and since we cannot experience God’s intervention in action, God cannot be the true cause of events. By asserting that the ultimate decision lies with the agent, Reid emphasized the significance of human subjective decision-making.
Hume also addressed philosophical issues related to the moral responsibility of agents. He believed that moral responsibility is not simply determined by external conditions but by the agent’s free will and choice. This means that humans can control their own actions and are therefore morally responsible for the consequences of those actions. Hume’s claims provided an important foundation for modern ethics, which emphasizes human moral autonomy and responsibility.
Leakey’s theory challenges the traditional understanding of causality and highlights the importance of the agent and free will. This provides important insights not only for explaining events in the physical world but also for understanding human behavior and moral responsibility.
