when we are firmly established in truthfulness, action accomplishes its desired end
YS II,36 translation by Alistair Shearer
Yamas - observances for living well - are the first of Patanjali's guidance for yogis; the second of the yamas is satya: truthfulness, honesty, sincerity, integrity.
Such a simple vow, the promise to be honest, but much more difficult to consistently fulfil. Small untruths litter our communications with each other. We lie about the reason we are late, or the reason we can't make an event, how much we spent on a shopping trip, how many glasses of wine we had last night, books we've read, how much time we spent fruitlessly surfing the internet. Other people may never know (or care) that we lied, but we know and we weigh ourselves down with it.
It can therefore be very liberating to tell the truth. In a sense, telling the truth allows us to be totally human, accepting of our weaknesses and all of the mistakes we make, and content with that perfect imperfectness. For example, if we admit that we are late because we overslept (instead of blaming the traffic), we are admitting to our mistake with the confidence that it doesn't have anything to do with who we are as a person. Everybody gets up late sometimes. We make the choice to be honest, rather than to find a false explanation that might conform more to what is expected of us (or what we expect from ourselves). We choose to feel better on the inside, rather than to look better on the outside.
There are times when it might be hurtful to tell the truth, so we temper our honesty with kindness (ahimsa) - if telling the truth will hurt somebody, then it might be better to say nothing. And satya doesn't give you license to go and tell the person you dislike all the bad thoughts and feelings you have about them. Be wise, be kind, do your best. As the Mahabharata advises:
"Speak the truth which is pleasant. Do not speak unpleasant truths.
Do not lie, even if the lies are pleasing to the ear."
Mahabharata translated by TKV Desikachar
Part of yoga practice is to reflect honestly on all of our actions. In the quiet stillness of yoga we confront ourselves and our actions with a clear eye and seek to understand the source of our behaviour, so that in future we might avoid the actions that cause ourselves and other people harm. If you can't be honest with anyone else about the way you feel, you can at least be honest with yourself. With careful scrutiny you are able to find the root of the matter and to discern why it made you feel and behave the way you did. Once you understand that, you are free to address the causes in the hope that you might behave more generously in future.
Satya is also about trusting yourself. You know who you are and what you need, admitting this to yourself is an important first step to admitting it to the world and to living by your own deepest truth. It's about integrity too: saying what you mean, meaning what you say and living up to it in practice.
According to the Yoga Sutras, when we live honestly, speak honestly and think honestly, other people take more notice of what we say because they know it to be true; moreover we do not waste energy on the concealment of untruths and secrets. Patanjali tells us in this sutra that through the practice of satya, we gain freedom.
"Tell the truth, tell the truth, tell the truth."