"To effect a confusion of ideas is an old scheme of the Devil. Not to understand clearly and precisely is generally the source of intellectual error. In time of schism and heresy, to cloud and distort the proper sense of words is a fruitful artifice of Satan, and it is as easy to lay snares for the intellectually proud as for the innocent. Every heresy in the Church bears testimony to Satan's success in deceiving the human intellect by obscuring and perverting the meaning of words. Arianism was a battle of words and owed its long continued success to its verbal chicanery. Pelagianism and Jansenism showed the same characteristic, and today Liberalism is as cunning and obscure as any of its heretical predecessors."
Fr. Felix Salvany, from his book, "Liberalism is a Sin", Chapter 12, Page 64