In my quest to learn more about yoga, I studied several overviews of this ancient tradition. One of the most comprehensive and informative appeared in Huston Smith's The Religions of Man. These are personal notes that I prepared from reading Smith's material: (Note 51)
Yoga is defined as a discipline designed to lead to an integration of the many selves into a single transcendent self. The normal pattern is for an individual to cast his approach to life in either a philosophical or a devotional mold, adapt his work to the chosen mold, and experiment to the extent that he can make time for it. This pattern reflects the four basic types of yoga:
Since this is the shortest, steepest path, this is not the most popular. The yogin identifies with the impersonal absolute that resides in the core of their being. Their lives follow where their minds lead as they seek to overcome ignorance with the sword of discrimination.
This process proceeds in three steps: 1) hearing (reading) to discover basic hypotheses, 2) thinking in prolonged, intensive reflection and 3) shifting to refocus from the passing to the eternal. This translated into being a witness as I learned how to become a Meditator in the World.
This is the most popular path. Here the yogin identifies with God as distinct from themselves. They seek to direct the geyser of love that lies at the base of every heart toward God. They insist on the otherness of God by adoring the divine with every element of their being.
Since they feel God's personality is indispensable, this approach can be characterized as the flight of the alone to the Alone. There are three features to this path: 1) repeating God's name through japam, 2) adapting all the attitudes of love and 3) worshiping one's chosen ideal.
Except for reproduction, the entire body converges toward muscles and their movement. Karma yoga takes advantage of this. The yogin seeks to find God in everyday affairs as readily as anywhere else. The subpaths are either Philosophical (reflective) or Devotional (affective).
In the philosophical subpath, the yogin draws a sharp line between the empirical self immersed in action and the external self which stands aloof from it. Work is performed in the spirit of complete detachment so as to be indifferent to the consequences that flow from work. Each thing is done as it comes as if it were the only thing to do.
In the devotional subpath, every action upon the external world has a correlative internal reaction on the doer. And every self centered act adds to ego coating while every selfless act lightens the ego's grasp. The yogin assumes "Thou art the doer, I am the instrument." There is no desire for the fruits of their actions.
This is considered the royal road. For the yogin, the affairs of the spirit can be approached just as empirically as outer nature. This approach assumes our true selves are vastly more wonderful than we now realize. There is a passion for the direct experience of our full selves.
The yogin undertakes a series of experiments and carefully observes the outcomes. They experiment on self rather than the world of external nature by practicing mental exercises and observing the effects on their spiritual condition. This leads the yogin to the direct personal experience of "the beyond that is within."
The experimental process has eight steps which transcend increasingly difficult barriers to realization: