One of the key dharma in Hinduism is to be Truthful always.
There are many interpretations to this. As a kid we are told that we should tell only truth, and nothing but the truth always. As we grow older, there is a doubt as to how we can tell the truth always. Some truths hurt people. Then is it wise to tell truth?
One of my relatives, who is an elderly lady, made it a point to tell bluntly on anyones face what she thinks about them. Most were uncomfortable with this habit of hers. But not me. I was from the same stable. The beauty of the situation was that this lady never minded if unpleasant truths about her were told to her. I, who was much younger to her, often used to tell her "Mami, your cooking is trash today" or like once when she sang a devotional song and asked my opinion, I retorted with "Well! you need to pour some oil down your throat as the sound is very scratchy". She took it with aplomb. The problem she and me faced, was that others just did not want go hear the truth. It made them uncomfortable. I used to be brutally frank with my students and used to blunt feedbacks. My logic was that students should be aware of their limitations, and my feedback should spur them to correct themselves. But the flip side was my students never wanted to know the truth about them.
Thus one needs to refrain oneself from telling truths all the time but use truth judiciously. If not telling the truth will result in a benefit for others/or telling the truth hurts others, it makes sense to keep quiet. Thus you need not tell untruth, but can avoid telling the truth for a broader cause.
Even Yudhishtiran, called Dharmaputra, the epitome of truthful living was forced to tell a half lie, "Aswathama hatha kunjaraha", by Srikrishnan during Kurukshetra as telling that would result in the mayhem caused by Dronacharya, and ultimately leading to the triumph of good over evil. In the same Kurukshetra, Srikrishnan was prepared to break his vow of not taking arms during the war for a greater good.
Thus the interpretation of 'Sathyam vadaa' means lead a life of truthfulness, but dont blurt out all truths, use truth judiciously, ensure that revealing truth do not hurt others and is for the benefit of the society and mankind. What is not acceptable is telling untruth for personal benefit.
Satyameva Jayathe!
