Student or Learner
A man can be blind; a man can be dead; a man can bemad. But the comparison is necessarily weak, after all. For it is theessence of madness to be unlike anything else in the world: which isperhaps why so many men wiser than we have traced it to another.
What does 'we have traced it to another' mean?
Please check your transcription of the quotation. There are mistakes in it like the running together of words and the possibility that you mean 'deaf' rather than 'dead'.
The meaning of the last sentence is a complete mystery to me.