Or else, putting spittle into the eyes of the blind man, He lays His hands upon him that he may see, because He has wiped away the blindness of the human race both by invisible gifts, and by the Sacrament of His assumed humanity; for the spittle, proceeding from the Head, points out the grace of the Holy Ghost. But though by one word He could cure the man wholly and all at once, still He cures him by degrees, that He may shew the greatness of the blindness of man, which can hardly, and only as it were step by step, be restored to light; and He exhibits to us His grace, by which He furthers each step towards perfection.
Again, whoever is weighed down by a blindness of such long continuance, that he is unable to distinguish between good and evil, sees as it were men like trees walking, because he sees the deeds of the multitude without the light of discretion.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).