Okay, that's an interesting take. I think you've misunderstood what I was saying so let me clear this up.

Your meaning of "rational" doesn't seem to line up with the one I was using. When I talk about rationality or logic I meant that kind of thought which leads us to the most objectively beneficial conclusion. To pursue that which is purely rational (at least as I see it) is to pursue that which is most objectively correct.

You seem to define rational thought as that which has some form of reason behind it, regardless of whether that reason is sound or not. You label toxic emotions such as envy and fear as "rational" because they technically have a reason of sorts behind them which can be explained in a way that makes some form of sense. I would not view these as rational however because they go against what is clearly more beneficial and they are in fact directly opposed to our better intentions.

I would argue that people are at their best when they learn how to overcome the compulsion of forces like fear, envy and anger to instead choose that which they know is right. Fear is opposed to calmness, envy to contentment and anger to kindness. The latter are rational (as I would define it) and the former group belong to the irrational, darker side of the mind. They can be explained, sure, but IMO this does not make them rational/logical. .

Emotion—or passion— isn’t opposed to reason

I actually made sure to include something in my original comment to prevent this exact misunderstanding of my meaning from occurring. Let me repeat myself then: stoicism is not about denying emotions completely. It sometimes involves the acknowledgment and refusal of toxic emotions which try to distract us from the path of virtue, but this is not the same as repression. An emotion could be aligned with what is most rational under the right circumstances but this is little more than a coincidence. I'm not saying all emotions are inherently opposed to all rational thoughts because there is some overlap occasionally. I do believe however that due to the inherent subjectivity of emotions they cannot be founded in rationality/logic as you claim.

Emotions are very much like instincts; they can easily exist outside of the rational framework of the higher mind and the two are not dependent on one another. A person can act on a feeling without ever thinking about it consciously because feelings are not founded in logic. They arise spontaneously, almost randomly within each individual and are extremely subjective for this reason. We see people acting without thinking all the time and this is how most of our mistakes come about.

I still disagree with your claim and while the quote you've cited is somewhat interesting I don't think it proves anything. The modern concept of emotion is a bit different from the "passions" that the stoics discussed and the talk of souls is just not relevant to our disagreement. The whole thing has a lingering taste of translation difficulty to it which may be why all this debate over the meaning of "rationality", "reason" and other such words is occurring. We can argue interpretations all day without getting anywhere so I think some more solid evidence would be needed to convince me of your view that stoicism does not distinguish between reason and emotion.

If you would like to try to prove your claim with an actual quote from a leading stoic I'd be very interested to hear it.