Sentence:  "They pretend," as I hear, "that the verses of Kabir have four different senses; illusion, spirit, intellect, and the exoteric doctrine of the Vedas;" but in this part of the world it is considered a ground for complaint if a man's writings admit of more than one interpretation. While England endeavors to cure the potato-rot, will not any endeavor to cure the brain-rot, which prevails so much more widely and <WSD>fatally</WSD>? 
Meaning of the word marked with <WSD> tags:  Ultimately, with finality or irrevocability, moving towards the demise of something.