The efficient cause, in our familiar case of the bronze statue, is the process by which its material takes the form of a statue. Each step along that journey of change, and each person who contributes to it, would together constitute the bronze statue’s efficient cause. The efficient cause of a chair would be the carpenter and their actions. To follow the logic even further, it could even be said that the chair’s efficient cause is everything that in any way contributed to the movement and/or change of its matter until it reached the form of a chair. This could include the sunlight and soil that helped the tree to grow, as well as the network of processes by which it was cut down and transported as a raw material.
In short, the efficient cause is related to the underlying movements which lead to any given phenomenon or event.
Digging a bit deeper into the efficient cause, however, it is notable that “Aristotle thinks of efficient causes as processes, rather than as static events,” and that “actual particular causes are not prior in time to their effects, but are co-temporaneous with them” (Shields, 2014). The formal cause also has a role to play in the efficient cause. Aristotle tells us that a “father” is the “cause of the child,” for example — although this is clearly an efficient cause, it is only made possible by the man’s form, which is then passed on to the child. As Politis explains, this is where Aristotle’s efficient cause diverges from our modern conception of causal movement: “For the modern conception of an efficient cause does not involve the supposition that it is the form of a thing that is such a cause” (2004).
4. The final cause
Finally, we reach the final cause. Aristotle describes the final cause as “‘that for the sake of which’ a thing is done, e.g., health is the cause of walking about” (Physics, fourth century BCE, [2017]). For Aristotle, the final cause is the ultimate purpose, or telos, that a given phenomenon has. As Shields explains, the final cause is a crucial component of Aristotle’s overall causal model: