Obviously a lie may be by act, as really as by word; as when a man is asked to tell the right road, and he silently points in the wrong direction. Obviously, also, the intention or purpose of deceiving is in the essence of the lie; for if a man says that which is not true, supposing it to be true, he makes a misstatement, but he does not lie; or, again, if he speaks an untruth playfully where no deception is wrought or intended, as by saying, when the mercury is below zero, that it is "good summer weather," there is no lie in the patent untruth. So far all are likely to be agreed; but when it comes to the question of that concealment which is in the realm of the lie, as distinct from right and proper concealment, there is more difficulty in making the lines of distinction clear to all minds. Yet those lines can be defined, and it is important that they should be. A witness on the stand in a court of law is bound by his oath, or his affirmation, to tell "the truth, the whole truth, and nothing but the truth," in the testimony that he gives in response to the questions asked of him. If, therefore, in the course of his testimony, he declares that he received five dollars for his share in a certain transaction, when in reality he received five hundred dollars, his concealment of the fact that he received a hundred times as much as he admits having received, is practically a lie, and is culpable as such. Any intentional concealment of essential facts in the matter at issue, in his answers to questions asked of him as a witness, is a lie in essence. But a person who is not before a court of justice is not necessarily bound to tell all the facts involved to every person whom he addresses, or who desires to have him do so; and therefore, while a concealment of facts which ought to be disclosed may be equivalent to a lie, there is such a thing as the concealment of facts which is not only allowable, but which is an unmistakable duty. And to know when concealment is right, and when it is wrong, is to know when concealment partakes of the nature of a lie, and when it is a totally different matter.