XXXVIII. (154) But since intoxication does not only display folly, which is the child of ignorance, but also utter insensibility; and since, again, wine is the cause of that insensibility which affects the body, while the cause of the insensibility of the soul is the ignorance of those things with which it is proper and natural to be acquainted; we must now say a few words about ignorance, reminding the reader of only the most important particulars relating to it. (155) To which, then, of the passions which affect the body shall we compare that passion in the soul which is called ignorance? To the deprivation of the organs of the external senses? Therefore all those, who have been injured in their eyes or ears, are no longer able to see or hear at all, but have no acquaintance with day or light, which are the only objects for the sake of which, if we are to tell the plain truth, life is really desirable, but dwell in lasting darkness and everlasting night, being made insensible to everything whether of small or great importance; men whom ordinary conversation naturally is accustomed to call infirm. (156) For even if all the other faculties of the rest of the body, should attain to the very extreme limit of strength and vigour, still, if they are tripped up, as it were, and deprived of their foundation by the deprivation of the eyes and ears, they will meet with a great fall, so as never again to be able to rise; for the things which support man and keep him erect are in name, indeed, the feet, but in reality the powers of hearing and seeing; and the man who possesses them in their complete integrity is awake and stands upright, but he who is deprived of them falls and will be utterly destroyed. (157) And ignorance does produce completely similar effects on the soul, depriving it of its faculties of seeing and of hearing, and allowing neither light nor reason to enter into it, lest the one should instruct it and the other should exhibit the truth to it. But shedding upon it dense darkness and abundant folly, it renders the most beautiful soul a deaf, and dumb, and lifeless stone.

XXXIX. (158) For knowledge, which is the opposite of ignorance, may be called, in a manner, the eyes and ears of the soul; for it applies the mind to what is said, and fixes its eyes upon things as they exist, and cannot endure to form a false judgment of anything which it either sees or hears. But it examines and carefully surveys every object which is worthy of being seen or heard, and even if it be necessary to sail or to travel over sea and land, it will traverse them to its furthest boundaries that it may see anything more important, or hear anything more modern; (159) for the love of knowledge admits of no hesitation or delay, it is an enemy to sleep and a friend to waking. Therefore, continually rousing up, and awakening, and sharpening the intellect, it compels it to roam about in every direction, where instruction is to be obtained, inspiring it with an avidity for hearing, and infusing into it an insatiable thirst for learning. (160) Therefore knowledge causes hearing and seeing, by means of which faculties success and rectitude of conduct are arrived at; for he who sees and hears, knowing what is expedient, chooses that, and rejecting the contrary is benefited by his knowledge. But ignorance causes to the soul a mutilation more grievous than the mutilation of the body, and is the cause of many errors, since it is unable to derive any assistance from without, either by foreseeing anything, or by any acuteness of hearing. Therefore, owing to its exceeding desolateness of condition, it is left utterly undefended and unprotected, and is exposed to the plots of all kinds of men and to dangers from all kinds of events. (161) Let us, then, never drink unmixed wine in such quantities as to cause insensibility to our outward senses, nor let us alienate ourselves to such a degree from knowledge as to diffuse ignorance, that vast and dense darkness, over our souls.