Peter Lombard, The Sentences, Book II:
The Holy Spirit, to purse the errors of these men and others like them and teach the discipline of truth, “signifies that God created the world at the beginning of the ages, and that he existed eternally before all ages. He commends the eternity and omnipotence of the one for whom to have willed is to make,” [Bede, Libri quatuor in principium Genesis 1,1] because, as we have said, new things exist by his will and goodness. And so let us believe “that the cause of created things, both celestial and earthly, visible and invisible, is nothing but the goodness of the Creator, who is the one and true God.” [Augustine, Enchiridion, c9] So great is his goodness that he, as the most highly good, wanted others to be sharers in his blessedness, by which he is eternally blessed: he saw that this could be shared and suffer no diminution at all. And so by goodness alone, and not by necessity, he willed to share that good, which he himself was and by which he was blessed, with another because it pertained to the most highly good to want to do good, and to the most omnipotent not to be able to be harmed.
Source: http://www.puritanboard.com/showthread.php/90447-Sharing-good-by-goodness, Comment #1