Summary
This quote suggests that reason serves as a balance between two extremes - the constraint of the bridle and the exuberance of the spur. It emphasizes the importance of using rational thought and logic to guide one's actions and decisions. It implies that reason enables individuals to find a middle ground between being overly controlled and being reckless. Essentially, this quote implies that reason serves as a mediator, allowing individuals to make well-thought-out choices that are both considerate and purposeful.