On 12th December, 1904, Pope St. Pius X gave an Allocution on the Fiftieth Anniversary of the Delaration of the Dogma of the Immaculate Conception:
Venerable brethren, there is only one piece of advice that I offer to you: watch over your seminaries and over candidates for the priesthood.
As you yourselves know, an air of independence which is fatal for souls is widely diffused in the world, and has found its way even within the sanctuary; it shows itself not only in relation to authority but also in regard to doctrine.
Because of it, some of our young clerics, animated by that spirit of unbridled criticism which holds sway at the present day, have come to lose all respect for the learning which comes from our great teachers, the Fathers and Doctors of the Church, the interpreters of revealed doctrine.
If ever you have in your seminary one of those new-style savants, get rid of him without delay; on no account impose hands upon him. You will always regret having ordained even one such person: never will you regret having excluded him. [Cf. Decree Vetuit of the Sacred Congregation of the Council (22 December 1905), forbidding in principle the admission into a seminary of any cleric or layman who was previously dismissed from another seminary by the local Ordinary (ASS XXXVIII, p. 407).]