The NeoSSPX have effectively “boiled the frog”: by slowly normalizing compromise among priests and the faithful, anyone who attends or participates becomes acclimated, neutralizing resistance and eroding awareness of the departures from Tradition.
An excerpt from Letters to Friends and Benefactors, Number 9, 1975, written by +Lefebvre. He clearly summarizes Liberalism.
[Rome has this disease...it is contagious...so why is neoSspx so friendly to these heretics? Td.]
https://fsspx.org/en/publications/september-1975-superior-generals-letter-9-36052*****
Principles of Liberalism
"...Let us first define in a few words the Liberalism of which the most typical historical example is Protestantism. Liberalism pretends to free man from any constraint not wished or accepted by himself.
First liberation: frees the intelligence from any objective truth imposed on it. The Truth must be accepted as differing according to the individual or group of individuals, so it is necessarily divided up. The making of the Truth and the search for it go on all the time. Nobody can claim to have exclusive or complete possession of it. It is obvious how contrary that is to Our Lord Jesus Christ and His Church.
Second liberation: frees the faith from any dogmas imposed on us, formulated in a definitive fashion, and which the intelligence and will must submit to. Dogmas, according to the Liberal, must be submitted to the test of reason and science, constantly, because science is constantly progressing. Hence it is impossible to admit any revealed truth defined once and for all. It will be noticed how opposed such a principle is to the Revelation of Our Lord and His divine authority.
Lastly,
Third liberation: frees us from the law. The law, according, to the Liberal, limits freedom and imposes on it a restraint first moral and then physical. The law and its restraint are an affront to human dignity and human conscience. Conscience is the supreme law. The Liberal confuses liberty with license. Our Lord Jesus Christ is the living Law, as He is the Word of God; it will be realized once more how deep runs the opposition between the Liberal and Our Lord.
Consequences of Liberalism
The consequences of Liberal principles are to destroy the philosophy of being and to refuse all definition of things, so as to shut oneself into nominalism or existentialism and evolutionism. Everything is subject to mutation and change.
A second consequence, as grave as the first, if not more so, is to deny the supernatural, and hence original sin,..
"