Thus, by preserving the unity of communion and the profession of faith with the Roman Pontiff, the church is a single flock under one Pastor. However, there is a difference between refusing to recognise the existence of an authority and refusing to submit to it in a particular instance. Those who refuse to accept the existence of papal prerogatives as such are guilty of schism and heresy. Those who refuse to submit to the exercise of a papal authority in a particular instance are only guilty of disobedience. A person cannot both believe that the pope has absolute authority and believe that the pope does not have authority in this or that particular case.
Actions speak louder than words.
It's quite easy to tell people to be good. It is another thing altogether to put those nice words into action. I or no other from the SSPX will dispute, and was merely an act of disobedience, not a denial of the authority of the successor of Peter. I shall treat the latter first. The fact that Archbishop Lefebvre's consecration of the bishops was an act of disobedience is without a doubt.