I-II, q. 12 a. 2
Whether intention is only of the last end?
Quaestio 12 · Of Intention
Objection 1: It would seem that intention is only of the last end. For it is said in the book of Prosper's Sentences (Sent. 100): "The intention of the heart is a cry to God." But God is the last end of the human heart. Therefore intention is always regards the last end.
Objection 2: Further, intention regards the end as the terminus, as stated above (Article [1], ad 4). But a terminus is something last. Therefore intention always regards the last end.
Objection 3: Further, just as intention regards the end, so does enjoyment. But enjoyment is always of the last end. Therefore intention is too.
On the contrary, There is but one last end of human wills, viz. Happiness, as stated above (Question [1], Article [7]). If, therefore, intentions were only of the last end, men would not have different intentions: which is evidently false.
I answer that, As stated above (Article [1], ad 4), intention regards the end as a terminus of the movement of the will. Now a terminus of movement may be taken in two ways. First, the very last terminus, when the movement comes to a stop; this is the terminus of the whole movement. Secondly, some point midway, which is the beginning of one part of the movement, and the end or terminus of the other. Thus in the movement from A to C through B, C is the last terminus, while B is a terminus, but not the last. And intention can be both. Consequently though intention is always of the end, it need not be always of the last end.
Reply to Objection 1: The intention of the heart is called a cry to God, not that God is always the object of intention, but because He sees our intention. Or because, when we pray, we direct our intention to God, which intention has the force of a cry.
Reply to Objection 2: A terminus is something last, not always in respect of the whole, but sometimes in respect of a part.
Reply to Objection 3: Enjoyment implies rest in the end; and this belongs to the last end alone. But intention implies movement towards an end, not rest. Wherefore the comparison proves nothing.