In some sense the king's writ of significavit was discretionary; but its issue could be enforced by excommunication or interdict.
The court which can award a sentence is said to possess as of common right a discretionary power of granting a reprieve.
The stages of the process (marked by the Valerio-Horatian laws of 449 B.C., the Publilian law of 339 B.C., and the Hortensian law of 287 B.C.) are unknown; but it is probable that the two first of the laws progressively weakened the discretionary power of senate and consuls in admitting such petitions; and that the Hortensian law fully recognized the right of resolutions of the plebs (plebiscita) to bind the whole community.
Not Even Appear That The Length Of The Intercalary Month Was Regulated By Any Certain Principle, For A Discretionary Power Was Left With The Pontiffs, To Whom The Care Of The Calendar Was Committed, To Intercalate More Or Fewer Days According As The Year Was Found To Differ More Or Less From The Celestial Motions.
It is conceivable that a pope of Boniface VIII.'s temperament would not submit kindly to any restriction of the discretionary power with which he was invested by tradition, and he endeavoured to make the cardinals dependent on him and even to dispense with their services as far as possible, only assembling them in consistory in cases of extreme necessity.