[130] but when it changes so as to assume one uniform white appearance, it displays an involuntary change; since the mind, entirely deprived of the power of reasoning, not having left in it one single seed to beget understanding, like a man in a mist or in deep darkness, sees nothing that ought to be done; but, like a blind man, falling without seeing his way before him into all kinds of error, endures continual falls and disasters one after another, in spite of all its efforts.