For nature therapy there is a multitude of philosophical theories that could be applied at many different levels. I like to think of nature therapy as having a framework on which to design, build and shape practice according to the knowledge and skills of the practitioner and their interaction with the person or people participating.
For me the framework has to start with a philosophy on life. It is here the Gaia hypothesis captures my heart. At its basic level Gaia poses the belief that everything in this universe is interconnected. What we do to one part of this balanced system impacts deeply on ourselves in some way. Many more people are reporting feeling unhappy, distressed and disassociated as we dive deeper into a technological era.
It appears to be fundamental to the human psyche to feel a sense of connection and people will seek this in different ways. This can be through religion, family, friends and even our pets. Contact with nature offers a guiding hand to lead the way back to feeling a sense of connection and peace. It offers an understanding of our place in this world and the universal laws that we are all, human, animal and plant, subject to.