An interview with Msgr. Lefebvre
Particularly noteworthy was this part:
Who placed these particular resolutions on the agenda?
I believe there were a number of cardinals assisted by theological experts who were in agreement with liberal ideas.
Who, for example?
Cardinal [Joseph] Frings from Germany, Cardinal [Franz] Koenig [from Austria]. These personalities had already gathered and discussed these resolutions before the Council, and it was their precise aim to make a compromise with the secular world, to introduce Illuminist and Modernist ideas into the Church doctrines.
[square-bracketed interpolations in the original]