This quote suggests that when we are driven by a strong purpose or enemy, even bad reasons can seem compelling, much like how a good piece of music can stir our emotions. It’s about how our perceptions and judgments can be clouded by our passions or motivations. When we are ‘marching against an enemy’, we are so focused and determined that we may overlook the quality of our reasons or the soundness of our strategies, much like how we might not critically evaluate the quality of the music we are marching to, as long as it stirs our spirit and keeps us moving forward.

In today’s world, this can be seen in various contexts, such as politics, where leaders and followers may be so driven by their cause or opposition to an ‘enemy’ that they may overlook the validity of their arguments or the ethics of their methods. It’s a reminder to step back and critically evaluate our reasons and strategies, regardless of how compelling our cause or enemy may be.

On a personal level, this quote may serve as a reminder to maintain objectivity and not let our emotions cloud our judgment. For instance, in our pursuit of personal goals or in our struggles against personal ‘enemies’ such as fear, insecurity, or procrastination, we might convince ourselves of certain beliefs or adopt certain strategies that may not be sound or beneficial in the long run. It’s important to remain self-aware and critically evaluate our thoughts and actions, rather than simply marching to the tune of our emotions or desires.