If a divine rationality infuses the entire world furthermore, your internal rationality is in harmony with that world…The Stoic impression of community therefore requires that what is internal about our individual rationality is also present in the universe around us.
Mr. Johncock writes an excellent article, and I would definitely recommend reading it, both for inspiration as well as to better understand ancient Stoic thought on the interplay between human nature, the universe, and the social imperative within Stoicism.
However, I find myself in disagreement with him if this understanding is confused with the limits of Stoic thought. My motivation for this disagreement is bound up by two things, first, my identification with Stoicism (although this is complex) and my inability to follow along with the belief in a pantheistic universe. As such, I would like to present my own thoughts as a possible substitute for this belief. I would suggest that what is important for the Stoic identity is not the particulars of underlying explanation, but that we successfully arrive at the same place, one of holistic unity with the world around us that forms within us a compelling sense of empathy and interdependence while motivating an accompanying sense of duty towards it.
I think it sufficient to find something that profoundly binds us to the world and the world to us (this mutuality seems important to me if we are to avoid a tendency towards paternalism), but I don't see it as necessarily having to be grounded in rationality. It could be something as simple (I say simple, yet it is nothing of the sort) as the causal web that so thoroughly entangles us and everything around us, one to the other, and an awareness of the interplay and harmony that exists between myself and the surrounding environment. I am in the world and the world is in me. The expansive empathy this produces in us can only stoke the desire to see that my actions make this world a better place for in its good I see my own. Likewise, my own push for perfection is impossible to realize without it containing within it the perfection of the world around me. My fate is inextricably linked with everything around me and is mutually determined.
This identification goes beyond rationality, although it is easiest to empathize with those things most like me. But I am more than rationality. I feel pain, and so I can empathize with that which can feel pain. I can love and lose that which I love, and so I sympathize with that which can also love and feel loss. Joy, pleasure, hurt, fear, yearning freedom, the instinct for life and happiness. I am not alone in this and where I can find it I gain a little insight, a little understanding. And with that understanding there is a bond between myself and the other, a piece of myself in them and they in me, and so my desire for a good life encompasses them and in acting upon this, I find my own life enriched and fulfilled.
Rather than losing the Stoic's "social nature", I find this holistic understanding of myself beyond rationality to expand it beyond the scope it might have attained if I had paid attention merely to that one aspect. Not that I think the ancient Stoic conception to be inferior, but I think there is room in Stoicism for those who cannot find in the world around them an overarching rationality, and that we can appreciate how our different conceptions of the world can bring us to the same fundamental insight about our place in the universe and all that this entails.