Living in agreement with oneself
The Stoic concept of Living in agreement with Nature has a second parameter. This also likely predates the concept of Nature itself, having been in some capacity mentioned by Zeno of Citium before Cleanthes brought Nature into the mix.
To Stoics, living in agreement with oneself came in the form of having internal consistency. It was important to have no vacillations or psychological inconsistencies in our internal belief systems. This ensured “agreement” or concordance with the self which in turn ensured happiness. The concept of virtues prescribed by Stoicism was a helpful curriculum guiding us to create and/or identify our internal belief systems.