This quote is a profound reflection on the nature of shadow, light, and darkness, both in a literal and metaphorical sense. In a literal sense, a shadow is created when light is obstructed, thus reducing both the light and the darkness. It is neither completely light nor completely dark, but exists in the space between the two, a mix of both elements.

In a metaphorical sense, this quote can be seen as a commentary on the human condition. Light and darkness can be seen as symbols for good and evil, or knowledge and ignorance. The shadow, then, represents the gray area between these extremes, where most of human experience lies. We are neither completely good nor completely evil, neither completely knowledgeable nor completely ignorant. We are a mix of both, existing in the shadow between these two extremes.

In today’s world, this idea can be applied in many ways. For instance, in our increasingly polarized society, it reminds us that most people and issues do not fit neatly into boxes labeled "good" or "evil". It encourages us to look beyond black-and-white thinking and to recognize the complexity and nuance in the world around us.

In terms of personal development, this quote can be a reminder to embrace our own complexity. Each of us has light and darkness within us, and it is the balance of these elements that makes us who we are. It can be easy to judge ourselves harshly for our flaws (our darkness), but it’s important to remember that our strengths (our light) are just as much a part of us. Similarly, we should strive to learn and grow (increase our light), but also recognize that it’s okay not to know everything (accept our darkness).

In essence, the shadow, as the space between light and darkness, is a space of balance, complexity, and nuance. It is a space where we can strive to be better, while also accepting ourselves as we are. It is a space where we can recognize the complexity in others, and in the world around us. It is, in many ways, the space where we truly live.