Yoga can be defined as 'an established set of guidelines and routines that one practices with the ultimate intention of reaching Divinity'. As the compiler of the Yoga Sutras, Patanjali incorporates all forms of Yoga practice to assist students with achieving a balanced body-mind-soul unit and to uplift individual and collective consciousness.
Patanjali Yoga can be broken down into 2 subdivisions, the Limbs and Sutras, which can then be broken down further. The first Limb of Patanjali Yoga is the Yama limb, which consists of 5 Yamas that focus on 'doing no harm (good behavior) to others'. The Satya Yama is the second Yama and translates to the 'practice of truthfulness, honesty and integrity in our thoughts, words and actions.'
There are many sides to Truth and non-truth; there have been/are/and will be times when Truth can do more harm than good, therefore, the 'truth' is/will not always the most harmless or integral response. This is an important perspective to absorb, along with the entire focus of the Yama Limb, which is 'to do no harm to others'. These principles of Truth are all considered in the Satya Yama.
When the definition of the Satya Yama is 'the practice of truthfulness, honesty and integrity in our thoughts, words and actions', one can identify their Truths or non-truths as being personalized responses to external, or internal, stimuli. Therefore, the starting point for the practice of this Yama is inside of oneself, at the tier of the mind/heart, as words and actions towards others are manifestations of thoughts/feelings.
To 'know thyself' is one of the objectives when practicing the Satya Yama. When one applies Truth, Honesty and Integrity to internal questions such as who am I really? or, am I happy?, one may find it excruciatingly difficult to answer without Courage. This is due to the existence of the Ego Self, defined as "... the division of the psyche that is conscious, most immediately controls thought and behavior, and is most in touch with external reality."
Each and every single one of us would probably not fully, 100%, agree with an-others observation or opinion of us, good or not good, which points to the fact that each and every single one of us, to some degree, 'knows thyself'. That is all the suggestion required when discussing the existence of the Ego Self and the True Self in relation to the Satya Yama. When one can answer their own questions of themselves Truth-fully and with Courage (am I, in Truth, happy?) then they begin to operate out of the True Self internally, and can then eventually, if not immediately, provide truthful or integral responses externally. This is why it is important to 'know thyself' and to then 'be true to thyself' on, at least, a casual level.
From internal Truth-full responses come external Truth-full responses, and the opportunity to further cultivate Honesty, Integrity and the desire to do no harm to others. When observing and practicing the Satya Yama, one can begin to see how the practice of Truth dismantles the Ego Self while, at the exact same time, builds up the True Self. The development of the True Self then fosters Truth-fullness, Honesty and Integrity in ones external responses, while protecting the heart of the Yama Limb by 'doing no harm' towards others' in ones truths.
In terms of the Satya Yama, Honesty is recognizing when a Truth-full response would cause more harm than good, and Integrity is choosing to respond in spirit of the honest observation. This causes a Harm-less response to others and thus, meets another ambition of the Yama. That is not to say one should respond with non-truth, but rather, to find the best response that fits the practice of this Yama. For example, when paying attention to the relationship Truth has with Honesty and Integrity, one will notice how often life invites them to respond Truth-fully, but from the Ego Self. One will also notice how often their responses to these invitations are not Harm-less.
For example, it could be said about a response to an offensive driver: 'That driver cut me off!! They deserved my (negative) response (a.k.a truth)!' True there was an 'offense' committed, but the negative, rude or aggressive behavior of others does not control and, therefore, should not influence one's ability to Truth-fully, Honestly, Integrally and Harmlessly respond. When we respond to negativity with negativity, we respond from the Ego Self, the only one who cares about the 'offense' or 'the offender.' However, referencing the offensive driver, if it were a matter of SAFETY, how would a response full of aggressive, negative Truth provide a solution? What would be the most integral response to the event? Notifying officials to deal with the situation properly one might say? So, the Satya Yama can be visualized; how Truth, Honesty and Integrity can harm or not harm, and how these ingredients can provide a solution or not.
Another factor to observe in practicing this Yama is how swiftly we tend to respond to external stimuli with our truths or non-truths, which is an element to be explored in observing and practicing the Satya Yama. Typically our truths or non-truths are immediately manifested, through expression, in the face of negativity. This is due to the even quicker mental/emotional reaction to negative stimuli and one not giving themselves space between stimuli and their response. It is in this space that one can collect their thoughts from True Self and respond with Truth-fullness, Honesty and Integrity. That is, one can consciously choose to do no harm in their response.
It could be said that Truths are steps taken on a Divine Path that guide an individual through their lifetime. One could then conceptualize that each step taken, or Truth expressed, either keeps one on course with True Self or it does not. With this in mind, one can see how each of their steps, their Truths or non-truths, creates the momentum required to move forward on, or off, their Divine Path. This is the blessing and gift of the Satya Yama.