XX. (65) This is that disposition in us which Moses characterised when he gave Cain his name, a name which being interpreted means possession, Cain himself being full of all folly or rather of all impiety; for instead of thinking that all possession belonged to God, he conceived that they all belonged to himself, though he was not only not able to possess even himself steadily, but he did not even know of what essence he consisted; but nevertheless he placed confidence in the outward senses, as being competent to attain the objects perceivable only by them. Let him tell us therefore how he will be able to avoid seeing wrongly, or being mistaken as to his hearing, or to escape even in any other of these outward senses. (66) And in truth it is inevitable that these errors should continually befall every one of us, even if we should happen to be endowed with the most accurately constructed organs possible; for it is difficult, or I might rather say impossible, for any one completely to avoid the natural blemishes and involuntary errors which arise, since the efficient causes of erroneous opinions are innumerable, both within us and around us, and outside of us, and since they are to be found in every mortal creature, man, therefore, very improperly conceives every thing to belong to himself, however proud he may be, and however high he may carry his head.