Certain young Athenians conspired against Diocles and Hippias, tyrants of Athens.  Diocles they slew; but Hippias, making his escape, avenged him.  Chion and Leonidas of Heraclea, disciples of Plato, conspired against the despots Clearchus and Satirus.  Clearchus fell, but Satirus survived and avenged him.  The Pazzi, of whom we have spoken so often, succeeded in murdering Giuliano only.  From such conspiracies, therefore, as are directed against more heads than one, all should abstain; for no good is to be got from them, whether for ourselves, for our country, or for any one else.  On the contrary, when those conspired against escape, they become harsher and more unsufferable than before, as, in the examples given, Florence, Athens, and Heraclea had cause to know.  True it is that the conspiracy contrived by Pelopidas for the liberation of his country, had to encounter every conceivable hindrance, and yet had the happiest end.  For Pelopidas had to deal, not with two tyrants only, but with ten; and so far from having their confidence, could not, being an outlaw, even approach them.  And yet he succeeded in coming to Thebes, in putting the tyrants to death, and in freeing his country.  But whatever he did was done with the aid of one of the counsellors of the tyrants, a certain Charon, through whom he had all facilities for executing his design.  Let none, however, take this case as a pattern; for that it was in truth a desperate attempt, and its success a marvel, was and is the opinion of all historians, who speak of it as a thing altogether extraordinary and unexampled.

The execution of a plot may be frustrated by some groundless alarm or unforeseen mischance occurring at the very moment when the scheme is to be carried out.  On the morning on which Brutus and his confederates were to slay Caesar, it so happened that Caesar talked for a great while with Cneus Pompilius Lenas, one of the conspirators; which some of the others observing, were in terror that Pompilius was divulging the conspiracy to Caesar; whose life they would therefore have attempted then and there, without waiting his arrival in the senate house, had they not been reassured by seeing that when the conference ended he showed no sign of unusual emotion.  False alarms of this sort are to be taken into account and allowed for, all the more that they are easily raised.  For he who has not a clear conscience is apt to assume that others are speaking of him.  A word used with a wholly different purpose, may throw his mind off its balance and lead him to fancy that reference is intended to the matter he is engaged on, and cause him either to betray the conspiracy by flight, or to derange its execution by anticipating the time fixed.  And the more there are privy to the conspiracy, the likelier is this to happen.