169. The exceptions to the rule above stated are, that motions to postpone (either to a day certain or indefinitely), to commit, or to amend, a principal question, may be amended, for the reason, that the useful character of amendment gives it a privilege of attaching itself to a secondary and privileged motion; that is, a subsidiary motion to carry out and improve another may be applied to that other, but a subsidiary motion to dispose of or suppress another is not admissible. Hence, the subsidiary motions above mentioned may be amended.
170. A previous question, however, cannot be amended; the nature of it not admitting of any change. Parliamentary usage has fixed its form to be, shall the main question be now put? that is at this instant; and, as the present instant is but one, it cannot admit of any modifications; and to change it to the next day or any other moment is without example or utility. For the same reasons, also, that the form of it is fixed by parliamentary usage, and is already as simple as it can be, a motion to lie on the table cannot be amended.
171. This motion is usually resorted to, when the assembly has something else before it, which claims its present attention, and therefore desires to lay aside a proposition for a short but indefinite time, reserving to itself the power to take it up when convenient. This motion takes precedence of and supersedes all the other subsidiary motions.
172. If decided in the affirmative, the principal motion, together with all the other motions, subsidiary and incidental, connected with it, is removed from before the assembly, until it is again taken up; which it may be, by motion and vote, at any time, when the assembly pleases.
173. If decided in the negative, the business proceeds in the same manner as if the motion had never been made.
174. This motion has already been described (63), and the nature and effect of it fully stated. It stands in an equal degree with all the other subsidiary motions, except the motion to lie on the table; and, consequently, if first moved, is not subject to be superseded by a motion to postpone, commit or amend.
175. If the previous question is moved before the others above mentioned, and put to the question, it has the effect to prevent those motions from being made at all; for, if decided affirmatively, to wit, that the main question shall now be put, it would of course be contrary to the decision of the assembly, and therefore against order, to postpone, commit, or amend; and if decided negatively, to wit, that the main question shall not now be put, this takes the main question out of the possession of the assembly, for the day, so that there is then nothing before it to postpone, commit, or amend.[23]