This quote uses the metaphor of a wheel and a brake to represent the dynamic of conflicting forces and their interdependence. The wheel represents motion, progress, and change, while the brake symbolizes resistance, control, and stability. Their common duty – to hurt one another – signifies their inherent tension and conflict. However, this ‘hurt’ isn’t necessarily negative; it’s essential for balance. The wheel needs the brake to prevent uncontrolled motion, and the brake needs the wheel for its function to have meaning.

Applying this concept to personal development, it suggests the importance of balancing ambition (the wheel) with self-control and restraint (the brake). While ambition drives us forward towards our goals, without restraint, it can lead to recklessness. On the other hand, too much restraint without ambition can result in stagnation. The ‘hurt’ they cause each other is the necessary friction that helps us maintain a balanced approach to personal growth.

In the context of today’s world, this idea can be seen in the balance between innovation (the wheel) and regulation (the brake). Innovation propels society forward, but unchecked, it can lead to unforeseen consequences. Regulation, on the other hand, ensures safety and fairness but can stifle progress if overly restrictive. The tension between these two forces shapes our societal progress, with the ‘hurt’ they inflict on each other serving as a mechanism for checks and balances.