Reading Aquinas.... clinically?

The summa theologiae on passions is a really weird text, or at least I have a really difficult time knowing how to respond to it as a genre. I think I end up taking a really clinical approach - inasmuch as I tried to systematize it to make some kind of sense of it. And there is a mechanics of passion, not with respect to the actual phenomenon, which involves influence and change (or perfection) or when it is a centre of the soul involves life - something self reflexive and engaged - none of which are so uncomplicated as action/reaction or proposition/response.
So what is the mechanics? Well one can see it in the question on pleasures - no-one can live without pleasures - and also in the remedies of sorrow. Part of the reason I became so depressed is that I did not realize the "necessity of pleasure for life" - that relaxing really is a remedy for sorrow. In reading the dynamics between sorrow and pleasure I came to have a map to situate my own sadnesses, which happened from prior loves which I could not see were getting met, but one cannot forget the habits of sadness which arise from not having pleasures to moderate them. Now it is impossible to say that a person lives without pleasures - even the saddest person has pleasures - even sadness has some suitability. But in terms of bigger sorrows superseding lesser pleasures, or in terms of one sadness hindering every pleasure, in terms of the circularity of depression which can be alleviated by the very rest which can also be ruined by anxieties that prevent the soul not only from fleeing what disturbs it, but from resting so that one can face it.
So where does the opening for really healing pleasures come in? Well there are some sorrows that Aquinas seems to recognize are not alleviated by any pleasure whatsoever - and this falls under penitence - which is sorrow proper - that concerns one's own evil - and this is the kind of sorrow that reappears in 57 or 59 - only the contrary pleasure can relieve it. So..

I am already getting out of the mechanics and into the really tough sorrow which minor things cannot relieve. But... even with the entry of the contrary pleasures of forgiveness, hope, and self esteem that arises from joy, there are still habits to be dealt with. There must be a therapy of pleasures which stretch, expand, open up something's capacity for pleasure that has too long been contracted and tensed. And this is where the mechanics comes in - one pleasure provides that little bit of rest that leaves one capable to do more, and if a greater sinking comes in, it takes only a very little pleasure to open up again because oneself is smaller. But sorrow is not the teacher I thought it was - it hinders teaching and learning, rather. The only way it can speed it up is on the part of compacting one's energy and effort towards expelling the causes of sorrow... but all its usefulness has left it by the time it reaches anxiety and acedia. And looking back over my own life the past couple of years, I had reason to appreciate and even to be happy about my sorrow at first - it was helping me to accomplish something! And the sense of activity was very strong, and activity brought pleasure. But as time went on and sorrow - even the proud sorrow that I had - began to sink further - I don't know why - and whether it is something that I would try to discover in confession or in therapy, of what genus it was, or both, at any rate, I developed an ongoing anxiety which falls along with the clinical definitions of depression - inability to concentrate, guilt complexes about resting, a kind of perpetual but un-focused studying - throwing myself more and more into projects with less and less success at them. And then acedia - the physical kind - I know that too.
But the point is, instead of conceiving a linear or historical or reflexive view alone - which could not provide me with a map of this - if I understand it according to a mechanics whereby it is not just pursuit and rest, but contraction and expansion along with pursuit and rest that does not forget the reflexive appetitive activity and the bodily effects.
So in other words, what is Aquinas doing? How would I describe his approach in a way that combines all these things? The word "organic" comes to mind as it expresses both the self-movement, the changes, and the mechanics that happen in an organism. But he is not a disinterested writer - it takes place in a summa tehologiae - after a prologue that proposes to treat of the human being as "he too is a princple of his actions" and these are the kinds of actions which he shares with the other animals - which are not most properly human (in the sense that other animals are excluded) and yet are most human at the same time.
But it is about ethics then. I should call it the organic entry of passions (organic sounds too much like the vegetative soul, though). He calls it the sensitive appetite.
If one could find a comprehensive way to explain appetite... Now, the field of ethics belongs to the voluntary, and the passions are not quite the voluntary, but the will and the passions sleep together or at least create together - it is a democracy...
it'll come... i'll keep putting things together..