In Book XII of St. Augustine’s autobiography Confessions, the Bishop of Hippo seeks to discuss Heaven and Earth. Specifically in chapters two through eight Augustine deals with the idea of God endowing what he calls ‘formless matter’ with form. Throughout this section he seems to borrow heavily from Plato’s ideas of what are known as The Forms; for Plato these ‘forms’ are eternally existing, they are independent of the mind, they are transcendent i.e. non-spatial and non-temporal, they are intelligible, and they are perfect. Furthermore, the form of the forms is the Good, incidentally this is the closest Plato ever comes to the idea of an immutable and eternally existing God. For Augustine the thought that the forms themselves are independently coeternal with God just doesn’t work, instead he postulates that the forms are actually God’s thoughts, and this concept is known as Divine Exemplarism. This all becomes very important when one seeks to understand what it is Augustine is attempting to explain as he talks of God’s creating of the world.
In Book XII, 3, 3 Augustine makes this statement in regard to God imparting form into formlessness:
“Lord, have you not taught me that before you imparted form and distinction to that formless matter there was nothing—no color, no shape, no body, no spirit? Yet not nothing at all, no, not that either, for there was some kind of formlessness with no differentiation.”
Setting aside for a moment Augustine’s assertion that there exists ‘formlessness with no differentiation,’ which requires a foray into astronomy, I want to focus on his idea of God imparting ‘form and distinction’ into formless matter. If the forms are indeed God’s thoughts/ideas, then in the act of creation God injects his, let’s say, idea of an apple tree into this formless matter, and it then takes on the shape of an apple tree. The apple tree that we see is thus, in the Platonic sense, imitating the form of an apple tree; the apple tree that we see is in the world of the becoming, while the form of an apple tree, which exists as an idea in God’s mind, is in the world of being. Again this borrows from Plato’s concept of the world of being and world of becoming, where the world of being is eternal and immutable, and the world of becoming is temporal and mutable; according to Plato, the world of becoming is a moving image of eternity. Augustine fleshes this concept out when he says that “the mutability of mutable things itself gives them their potential to receive all those forms into which mutable things can be changed.”
It should be noted that where Plato, a pagan, and Augustine, a Christian, split is the ontological aspects of the forms. For Plato, as previously stated, the forms are eternal, and are thus equal to God, for Plato God would loosely be what he calls the Good; Plato does not designate the Good as God. For Augustine, although the forms are God’s thoughts, when they take shape the created form is neither coeternal nor coequal with God.
Let me very briefly make a comment about what Augustine calls ‘formless matter’ or a ‘nothing-something.’ Augustine addresses the statement in Genesis 1 where it says that the Earth was void and without form; in the translation he had it uses the phrasing “invisible and unorganized.” In astronomy there is a theory that exists in order to account for the mass and gravitational events in the universe that cannot be attributed to visible objects. This theory posits that this invisible substance is dark matter, and the gravitational events are attributed to dark energy. Little is known about dark matter and dark energy, but it is theorized to account for 95 percent of the composition of the universe. Some of the theories surrounding dark matter and dark energy seem to fit with Augustine’s ideas concerning ‘formless matter.’
Augustine’s ideas about matter, intelligible forms, and so on provide compelling insights into the creation of our universe, and the power and majesty of God.
 All quotes are taken from: Maria Boulding, trans., The Works of Saint Augustine: A Translation for the 21st Century; The Confessions, ed. John E. Rotelle (New York: New City Press, 1997)