I am reading Alfred North Whitehead’s The Function of Reason, and am moved by his notion of reason. Whitehead is careful not to fully define reason, for it turns it into a phrase. Yet he does give an initial, poetic understanding: The function of reason is to promote the art of life.
If one were to take the notion that God is the cause of all things (which brings in its own issues), or, if one states that all causes in the world are the result of natural, physical causes, does not provide the function of reason. These are but efficient causes. An efficient cause is the primary source of the change. For example, my hand moves the water bottle from one place to another. My hand X is the efficient cause of the movement of the water bottle Y. It is an efficient cause since what we see is the hand moving the bottle. This is useful in the world of science, when we look to describe how things come to be. Here, reason is used as an immediate method of action (11).
But can this be used to describe a complete understanding of why things are the way they are? Whitehead doesn’t believe so. In fact, he agrees with Plato that there is another cause, a final cause, which is a necessary component for why things are the way they are. If physics describes the efficient cause for why things happens, it doesn’t get to the more difficult reason of why it was even done in the first place. The final cause is its aim.