63. Every creature, then, is subject to change, not only such as has been changed by some sin or condition of the outward elements, but also such as can be liable to corruption by a fault of nature, though by careful discipline it be not yet so; for, as we have shown in a former treatise, De Fid. III. 3. the nature of Angels evidently can be changed. It is certainly fitting to judge that such as is the nature of one, such also is that of others. The nature of the rest, then, is capable of change, but the discipline is better.