This article from Unam Sanctam Catholicam is simply a must-read for any Catholic with a two-bit theological opinion.
I myself am chastened. Severely.
Please read the whole thing:
“This post’s title does not refer to the Greek schism, nor to the Great Western Schism of the 15th century, nor even to the tremendous modernist crisis within the Church today. The schism I am referring to is the unfortunate fracture between theology and ascesis, between spirituality and mortification. The more I reflect upon it, the more I am convinced that this division is at the heart of all our other problems, even the modernist crisis …”