This quote highlights the paradox of human progress. It suggests that while mankind has made significant advancements in various fields like technology, medicine, and science, we have not been able to gain control over our own selves. This control could refer to our emotions, our desires, our thoughts, or our actions. Despite our outer progress, our inner selves remain a mystery and a challenge.

In a broader perspective, this quote also highlights the human tendency to focus on external development while neglecting internal growth. We have harnessed the power of the atom, but struggle to control our anger, fear, prejudice, and hatred. In essence, we have been able to conquer the world outside, but not the world within.

Applying this to today’s world, we see this paradox more than ever. With rapid technological advancements, we have gained immense power to shape our external world. Yet, we see an increase in mental health issues, emotional instability, and societal discord. This suggests that our internal world is not keeping pace with our external progress.

In terms of personal development, this quote underscores the importance of self-mastery. While it is important to strive for external achievements, it is equally, if not more, important to develop self-control, emotional intelligence, and inner peace. Self-mastery is the key to true power and freedom. It allows us to respond rather than react, to choose rather than be driven by our impulses, and to create rather than be shaped by our circumstances.

In conclusion, while we should continue to strive for progress in every sphere, we should not neglect the sphere within us. As we grow in power externally, we must also grow in power over ourselves. Only then can we truly harness the full potential of our power.