Sentence:  ... "Intemperance" and "Superfluity" <WSD>beclouds</WSD> the Mind, dulls the edge of the Apprehension, and brings upon it an "unmanly Languor", bearing down all the noble Faculties of the Soul into Ignorance and Stupidity ... 
Meaning of the word marked with <WSD> tags:  To cause to become obscure or muddled.