CHAPTER III. God the Creator of All; and the Goodness of All Creation
9. Wherefore, when it is asked what we ought to believe in matters of religion, the answer is not to be sought in the exploration of the nature of things [rerum natura], after the manner of those whom the Greeks called "physicists."  Nor should we be dismayed if Christians are ignorant about the properties and the number of the basic elements of nature, or about the motion, order, and deviations of the stars, the map of the heavens, the kinds and nature of animals, plants, stones, springs, rivers, and mountains; about the divisions of space and time, about the signs of impending storms, and the myriad other things which these "physicists" have come to understand, or think they have. For even these men, gifted with such superior insight, with their ardor in study and their abundant leisure, exploring some of these matters by human conjecture and others through historical inquiry, have not yet learned everything there is to know. For that matter, many of the things they are so proud to have discovered are more often matters of opinion than of verified knowledge.
For the Christian, it is enough to believe that the cause of all created things, whether in heaven or on earth, whether visible or invisible, is nothing other than the goodness of the Creator, who is the one and the true God.  Further, the Christian believes that nothing exists save God himself and what comes from him; and he believes that God is triune, i.e., the Father, and the Son begotten of the Father, and the Holy Spirit proceeding from the same Father, but one and the same Spirit of the Father and the Son.
10. By this Trinity, supremely and equally and immutably good, were all things created. But they were not created supremely, equally, nor immutably good. Still, each single created thing is good, and taken as a whole they are very good, because together they constitute a universe of admirable beauty.
11. In this universe, even what is called evil, when it is rightly ordered and kept in its place, commends the good more eminently, since good things yield greater pleasure and praise when compared to the bad things. For the Omnipotent God, whom even the heathen acknowledge as the Supreme Power over all, would not allow any evil in his works, unless in his omnipotence and goodness, as the Supreme Good, he is able to bring forth good out of evil. What, after all, is anything we call evil except the privation of good? In animal bodies, for instance, sickness and wounds are nothing but the privation of health. When a cure is effected, the evils which were present (i.e., the sickness and the wounds) do not retreat and go elsewhere. Rather, they simply do not exist any more. For such evil is not a substance; the wound or the disease is a defect of the bodily substance which, as a substance, is good. Evil, then, is an accident, i.e., a privation of that good which is called health. Thus, whatever defects there are in a soul are privations of a natural good. When a cure takes place, they are not transferred elsewhere but, since they are no longer present in the state of health, they no longer exist at all. 
 One of the standard titles of early Greek philosophical treatises was [[pi]] [[epsilon]] [[rho]] [[iota]] [[phi]][[nu]][[sigma]][[epsilon]][[omega]][[zeta]], which would translate into Latin as De rerum natura. This is, in fact, the title of Lucretius' famous poem, the greatest philosophical work written in classical Latin.
 This basic motif appears everywhere in Augustine's thought as the very foundation of his whole system.
 This section (Chs. III and IV) is the most explicit statement of a major motif which pervades the whole of Augustinian metaphysics. We see it in his earliest writings, Soliloquies, 1, 2, and De ordine, II, 7. It is obviously a part of the Neoplatonic heritage which Augustine appropriated for his Christian philosophy. The good is positive, constructive, essential; evil is privative, destructive, parasitic on the good. It has its origin, not in nature, but in the will. Cf. Confessions, Bk. VII, Chs. III, V, XII-XVI; On Continence, 14-16; On the Gospel of John, Tractate XCVIII, 7; City of God, XI, 17; XII, 7-9.