The sense in which we use the term "ecological" is associated with a specific philosophical school, founded in the early 1970s by the Norwegian philosopher Arne Naess (1912-2009) with the distinction between "shallow" and "deep" ecology. Since then, this distinction has been widely accepted as a very useful term for referring to a major division within contemporary environmental thought.
Shallow ecology is anthropocentric, or human-centered. It views humans as above or outside of nature, as the source of all value, and ascribes only instrumental, or "use," value to nature. Deep ecology does not separate humans — nor anything else — from the natural environment. It does sees the world not as a collection of isolated objects but as a network of phenomena that are fundamentally interconnected and interdependent. Deep ecology recognizes the intrinsic value of all living beings and views humans as just one particular strand in the web of life.
Ultimately, deep ecological awareness is spiritual awareness. When the concept of the human spirit is understood as the mode of consciousness in which the individual feels a sense of belonging, of connectedness, to the cosmos as a whole, it becomes clear that ecological awareness is spiritual in its deepest essence. Hence, the emerging new vision of reality, based on deep ecological awareness, is consistent with the so-called "perennial philosophy" of spiritual traditions.
There is another way in which Arne Naess characterized deep ecology. "The essence of deep ecology," he wrote, "is to ask deeper questions." This is also the essence of a paradigm shift. We need to be prepared to question every single aspect of the old paradigm. Eventually, we will not need to abandon all our old concepts and ideas, but before we know that we need to be willing to question everything. So, deep ecology asks profound questions about the very foundations of our modern, scientific, industrial, growth-oriented, materialistic worldview and way of life. It questions this entire paradigm from an ecological perspective: from the perspective of our relationships to one another, to future generations, and to the web of life of which we are part.
From the book "The Systems View of Life: A Unifying Vision" by Fritjof Capra and Pier Luigi Luisi.