Sat and Satya (expressing Sat) can be traced back to the hymns of the Rig Veda. The poet meditators would have the vision of god and then speak Satya, the transcendent truth. The hearers of those words could be awakened by them to the vision of god. Someone who could speak those words was called a Brahmin, one who could access Brahman, the substratum of creation. Vedic rituals were designed to give the participants the experience of this deeper truth (Sat).
In the Bhagavad Gita (17.23), Krishna proclaims “’Aum tat sat’ is said to be the threefold path to ultimate truth. The different paths to spirit were created from this in the ancient time.“ One interpretation of this is: if you want to find god, meditate on AUM, and practice to see the true (sat) and the real (tat) in every situation. Choose what is true/real over the fantasies and imaginations of the mind.
This ties in very well with Patanjali’s definition of stopping the mind’s vacillations through restraint so that the svarupa (true or essential nature) appears. Patanjali gives us an effect from the practice of truth that ties in with the concept of Satya from the Vedas: When truth to all beings is perfected, the effectiveness of his words and acts is immediately to be seen (YS 2.36).
Some teachers in the past have interpreted this to mean that when someone has mastered Satya, whatever they say becomes true. Satya becomes a siddhi or magical effect from the practice. Swami Kripalu, however, believed in two kinds of truth: social truth (pravritti dharma) and universal truth (nivritti dharma).
Social truth is life-affirming and uplifting for everyone involved and leads to success in the world and healthy relationships. Ultimate truth leads one beyond social life into an existential world that was believed to be life transcendent, the world of enlightenment. Ultimate truth is very difficult to see and digest. Many years of intense yoga practice was considered necessary.
It is a social truth that one can eat in ways that will maintain health into old age. Living by and acting on this truth gives one a feeling of confidence and control over destiny. One has many opportunities to practice each day and thus to grow in knowledge of one’s desires and how to meet them appropriately.
It is an ultimate truth that one could die at any moment. Most of us would find it depressing to dwell on this fact. A renunciate yogi practicing ultimate truth wanted to fully accept this fact but in a way that allowed him to treasure each moment of the life unfolding before him.
Swami Kripalu spoke of truth as a bright light that was too strong for us to look at. He encouraged us to remove a little untruth from our lives. His guidance was to do experiments with truth and grow in our capacity to see ever stronger levels of truth.