As children, we are always told not to lie. We are told to tell the truth, to not tell lies, and that those who deal in lies are evil. And yet as we mature, we ironically come to terms with the fact that what we were told as a child was a lie; a contradiction within itself. A great example of this is the American court system. Every day millions of people walk into a room of law, swear to tell the truth, the whole truth, and nothing but the truth, and yet half of them lie.
What is the truth anyways? And who is to say what is true and what is not true? There lies perhaps a boundary between undeniable fact and subjective truth. Things are not always so black and white. Take for instance "those that murder are evil", is that true? Perhaps in the context of mindless slaughter, yes. But perhaps in the case of war, no. The truth of a matter is often opinionated and very much something to be debated upon.
But why is that the truth? In fact, why is the truth the truth? This invariably comes to rest upon the eyes of the observers and the status of the society in which a truth is presented. Different societies and different eras have different views on any topic at hand.