35 On the other hand, not a few, impelled by a false zeal, or - what is more blameworthy still - affecting sentiments which their conduct belies, take upon themselves to act a part which does not belong to them. They would faire see the Church's mode of action influenced by their ideas and their judgment to such an extent that everything done otherwise they take ill or accept with repugnance. Some, yet again, expend their energies in fruitless contention, being worthy of blame equally with the former. To act in such manner is nor to follow lawful authority but to forestall it, and, unauthorized, assume the duties of the spiritual rulers, to the great detriment of the order which God established in His Church to be observed forever, and which He does not permit to be violated with impunity by any one, whoever he may be.
Source: Sapientiae Christianae (Vatican.va)