In a comment below, Steven Riddle brings up a subject I've been sort of poking at in my own mind:
Let's talk about the implications of St. Thomas's assertion (which I believe to be true) that God is simple, not composed of parts, and unite that to the concept that God is Love, without making love simplicity and without reducing God merely to the human notion of love, because although God is simple and God is Love, God is uniate and a lot more things than love. As with a diamond, we can choose to view the whole or look at a single facet and call that the whole.
I've been intrigued by the implications of the encyclical and aspects of Thomistic philosophy since the encyclical came out.
By "poking at it," I mean "telling myself there's are some implications I have no clue at all about." That said:
When I read what St. Thomas wrote about God's simplicity, I recalled a reflection that you wrote a while ago about the fractaline nature of the Eucharist: any part contains the whole. This is what I understand St. Thomas' concept of simplicity to mean. So, could it follow that any act of love -- no matter how "small" -- contains some sort of fullness of love? At least in as much as we mean agape love, this might be related to the Little Way of St. Therese. Perhaps any act of sacrificial love contains God, not just a part of God -- since He can not in His simplicity be subdivided -- but God.
I'll buy that, except for that verb "contains." Though we know what we mean (or at least what we mean to mean), the Eucharistic species doesn't really "contain" Christ's Body, Blood, Soul, and Divinity, in the ordinary meaning of the word. Or even in an extraordinary meaning of the word.
Instead, we talk about Christ's "presence in" the Eucharist, or that the Eucharist "is" Christ's Body and Blood, for some sacramental sense of "presence" and "being."
So we might say that God -- Father, Son, and Holy Spirit -- is somehow wholly present in every act of sacrificial love, and adopt an understanding of the Scriptural formula, "if we love one another, God remains in us," that is broad (i.e., not limiting the "love" to some sort of super-refined act only bilocating saints perform), non-tautological (i.e., not defining the "love" as "the sort of love through which God remains in us"), and literal (i.e., our loving one another, in and of itself, really and for true, means that God remains in us; no conditionals or exceptions necessary).
Now, to fold it back toward Steven's point that God is a lot more things than love, we might ask whether God's presence in an act of love is somehow essentially different from God's presence in any other act. As I've been mentioning, we read that "God is light" in the same epistle that gives us "God is love," so there's reason to be cautious about making theological claims based on grammatical data. For that matter, isn't "God Is" even more fundamental than "God is love"?