As to the dangers attending the execution of plots, these result either from some change made in the plan, or from a failure in courage on the part of him who is to carry it out; or else from some mistake he falls into through want of foresight, or from his not giving the affair its finishing stroke, as when some are left alive whom it was meant to put to death. Now, nothing causes so much disturbance and hindrance in human affairs, as to be forced, at a moment’s notice and without time allowed for reflection, to vary your plan of action and adopt a different one from that fixed on at the first. And if such changes cause confusion anywhere, it is in matters appertaining to war, and in enterprises of the kind we are now speaking of; for in such affairs as these, there is nothing so essential as that men be prepared to do the exact thing intrusted to them. But when men have for many days together turned their whole thoughts to doing a thing in a certain way and in a certain order, and the way and order are suddenly altered, it is impossible but that they should be disconcerted and the whole scheme ruined. For which reason, it is far better to do everything in accordance with the preconcerted plan, though it be seen to be attended with some disadvantages, than, in order to escape these, to involve yourself in an infinity of dangers. And this will happen when you depart from your original design without time given to form a new one. For when time is given you may manage as you please. The conspiracy of the Pazzi against Lorenzo and Giuliano de’ Medici is well known. The scheme agreed on was to give a banquet to the Cardinal S. Giorgio, at which the brothers should be put to death. To each of the conspirators a part was assigned: to one the murder, to another the seizure of the palace, while a third was to ride through the streets and call on the people to free themselves. But it so chanced that at a time when the Pazzi, the Medici, and the Cardinal were all assembled in the cathedral church of Florence to hear High Mass, it became known that Giuliano would not be present at the banquet; whereupon the conspirators, laying their heads together, resolved to do in church what they were to have done elsewhere. This, however, deranged the whole scheme. For Giovambattista of Montesecco, would have no hand in the murder if it was to be done in a church; and the whole distribution of parts had in consequence to be changed; when, as those to whom the new parts were assigned had no time allowed them to nerve their minds to their new tasks, they managed matters so badly that they were overpowered in their attempt.