Mere skill in reasoning does not make a person’s intelligence pure, for since the fall our intelligence has been corrupted by evil thoughts. The materialistic and wordy spirit of the wisdom of this world may lead us to speak about ever wider spheres of knowledge, but it renders our thoughts increasingly crude and uncouth. This combination of well-informed talk and crude thought falls far short of real wisdom and contemplation, as well as of undivided and unified knowledge.
~St Gregory of Sinai
Prayerful Life 