Once the sin/grace/God dynamic comes onto the scene, the distinction between emotion and rationality is pretty predictable in the broadstrokes: both are from God and therefore good, but both are fallen, and therefore can only be aligned toward their proper purpose (God) with God's grace.

I think (if I'm reading the above correctly) that Gibson is parting instinct/emotion and reason in a much more durable way than ancient writers, especially pre-Christian ones, would. And that's in large part due to their anthropological optimism on how we can train ourselves to not just overcome emotional response, but to use it in pursuit of the good.

The book, which is by a Finnish writer (Simo Knuutila) that I've never read before, spends just a TON of time on lit review. So if the topic interests you then I'd definitely recommend the book even just for its value in providing an overview of the development of the idea of "emotion." The short take is that Plato and then Aristotle saw emotion as a durable part of the rational human experience and sought to rigorously categorize them in the service of making them useful. Plato divided the soul into a rational, appetitive, and and sprited parts - with the ideal of the rational part governing the entire soul in its love of wisdom. But "love" is an emotion and that ideal isn't dependent on the sublimation of the other two aspects so much as cooperation in pursuit of the good of philosophical wisdom.

I think he over-reads the Stoics in contrasting them to Plato and Aristotle, where I'd rather see them in inheriting the tradition that makes emotions controllable in service of (a different, in their case) good. But the ancient period isn't my specialty at all, so I'm probably wrong about that. Though it also means I've been teaching the Stoics wrong so... oops?

I'm having a really tough time riddling out what he's trying to do with Aristotle and his respondents, outside of detailing Aristotle's tireless cataloguing of emotion. Here's an excerpt:

"Fear is divided into six species. Shrinking (oknos) is fear of taking action; terror (kataplexis) is fear arising from some strong impression; consternation (ekplexis) is fear arising from an impression without precedent; anxiety (agonia) is helpless fear of failure; shyness (aidos) is a fear due to an expected reproach...."

He does his usual due dilligence with the ante-Nicene writers, but everything changes in this field, in Christianity, and in all of the west, with Augustine. Genealogy of emotion folds into genealogy of religion which folds into genealogy of sin which all folds into a careful consideration of human capability. The takeaway is that emotions are good, but since they're ours, they're also fallen. We suffer under cognitive gaps (mis-understanding the good and seeing it elsewhere than God) but they're not as powerful as emotional gaps (loving something besides God) and Augustine piggybacks (somewhat controversially at the time) on the ancient writers categorization of emotion in order to simultaneously:

-describe that they can be aligned toward God (though not a whole lot on how - that's a later medieval development, mostly under the monastic movements)

-lament how little KNOWING this does for us and requiring that God's grace align them toward God for us

In any case, it's a good book for it's overview of all these writers. I'm not fully on board with all of his analyses, but you can't get this much content on the topic packed into 300 pages elsewhere.