It is not necessary that the abettor should actually lend a hand, that he should take a part in the act itself; if he be present ready to assist, that is assisting....  The law is, that being ready to assist is assisting, if the party has the power to assist, in case of need.  It is so stated by Foster, who is a high authority.  “If A happeneth to be present at a murder, for instance, and taketh no part in it, nor endeavoreth to prevent it, nor apprehendeth the murderer, nor levyeth hue and cry after him, this strange behavior of his, though highly criminal, will not of itself render him either principal or accessory.”  “But if a fact amounting to murder should be committed in prosecution of some unlawful purpose, though it were but a bare trespass, to which A in the case last stated had consented, and he had gone in order to give assistance, if need were, for carrying it into execution, this would have amounted to murder in him, and in every person present and joining with him.”  “If the fact was committed in prosecution of the original purpose which was unlawful, the whole party will be involved in the guilt of him who gave the blow.  For in combinations of this kind, the mortal stroke, though given by one of the party, is considered in the eye of the law, and of sound reason too, as given by every individual present and abetting.  The person actually giving the stroke is no more than the hand or instrument by which the others strike.”  The author, in speaking of being present, means actual presence; not actual in opposition to constructive, for the law knows no such distinction.  There is but one presence, and this is the situation from which aid, or supposed aid, may be rendered.  The law does not say where the person is to go, or how near he is to go, but that he must be where he may give assistance, or where the perpetrator may believe that he may be assisted by him.  Suppose that he is acquainted with the design of the murderer, and has a knowledge of the time when it is to be carried into effect, and goes out with a view to render assistance, if need be; why, then, even though the murderer does not know of this, the person so going out will be an abettor in the murder.

20.  Definition through the History of the Case.  In some cases the easiest way to put before your readers the precise details or limitations implied in a term is through a brief review of the history of the question.  In the Lincoln-Douglas debates Lincoln was constantly showing that Douglas’s use of the term “popular sovereignty” must be understood in the light of the whole history of the slavery question; that it meant one thing—­what Douglas intended it to mean—­if the history of the question before 1850 were left out of sight; but that it meant a wholly different thing if the steady encroachment of the slave power from the Missouri Compromise of 1820 on were taken into account.  And Lincoln showed that in reality “popular sovereignty” had come to mean a power oh the part of the people of a territory to introduce slavery, but not to exclude it.[12] In our own day “progressive” has a different meaning when applied to a Republican from Kansas and to one from Massachusetts or New York.