how to detect lies

Detecting Lies
Come on, we have among us, you can say: do you have never claimed to your boss that you were late because the bus was not spent, or because your car refused to start while you had simply forgotten to get up? Do you have never claimed to your friend that the store was out, and then you had simply forgotten the date of his birthday? All of us have already lain!
There are cases, or a little lie does nothing wrong, and we can take advantage of very delicate situations. Sometimes, the truth would make so many complications; a small deviation from the truth would solve so many problems that it is very difficult to resist the temptation.
First we can see why lying, then how to lie perfectly, and finally how to detect a lie. I/ why we lie?
Have you ever tried to imagine what your life would be if you never lie? When anything that came out of your mouth was nothing but the plain truth, naked and without artifice?
Perhaps you would be alone, without friend, perhaps on the street, and certainly in a position unenviable. I would say even more, the lie is a necessary ingredient in community life.
Most people do not like to receive brutal truth and potentially offensive. That is why people say some little lies, intended to overcome their sensitivities, not to insult or offend. These lies are committed to a good cause.
Unfortunately, there are also the malicious lies, intended to serve the interest of the person who makes those lies. Those, it would be interesting to know to detect them.
II/ Lessons to know how lying.
Liars are too often betrayed by their body language. The intent to deceive others is generally accompanied by significant signals more or less pronounced, which are all clues that might betray you. The first point is to hide is body language! To be convincing, the liar must avoid at all costs leaving drag these signs. To do