Acharya Prashant explains that the definition of yoga must start from one's definition of oneself. If a person is convinced they are the body, then yoga must be physical. While physical yoga is the right solution for physical troubles like a sore knee or an inflamed back, the primary problems of mankind in the 21st century are mental. He observes that the mind of the average person is extremely unhealthy and restless, making the yoga of the mind a necessity. Although medical science can handle physical and some psychosomatic issues, it cannot address the bulk of mankind's problems which lie within the mind. He states that while yoga literally means union, it is often given fancy definitions that lack scriptural basis. Real yoga involves an inquiry into what the restless mind wants to dissolve into or unite with. In the face of modern challenges like the extinction of species and climate catastrophe, it is vital to understand the mind's tendency for blind consumption. People attempt to satiate their appetite through material consumption, yet no amount of material goods brings final peace. True yoga is an inquiry into who we are and what we really want, serving as the only thing that can save humanity from its current destructive path.