Sentence:  By acting "in loco parentis", the written word performs its own usurpations of generating authority and generated meanings. Therefore, after the brothers demolish the authority of the word as written, they ar able to substitute alternative authorities: the word as spoken, the word as added, the word as <WSD>troped</WSD>, the word as altered, the word as hidden. 
Meaning of the word marked with <WSD> tags:  To think or write in terms of tropes.