Otherwise; faith is likened to a light, because by it the goings of the inner man, that is, action, are lightened, that he should not stumble according to that, “Thy word is a light to my feet.” [Ps 119:105] If that then be pure and single, the whole body is light; but if defiled, the whole body will be dark. Yet otherwise; by the light may be understood the ruler of the Church, who may be well called the eye, as he it is that ought to see that wholesome things be provided for the people under him, which are understood by the body. If then the ruler of the Church err, how much more will the people subject to him err?
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: ap. Gloss. ord.