Logos

... the universe is organized according to rational principles, the Logos. This can be interpreted as God (for instance in Epictetus), but also simply as the idea that Nature is understandable by way of rationality (which is why we can scientifically investigate it).

Stoic philosophers identified the term logos with the divine animating principle pervading the Universe… The Stoics also spoke of the logos spermatikos (the generative principle of the Universe)... Stoic philosophy began with Zeno of Citium c. 300 BC, in which the logos was the active reason pervading and animating the Universe. It was conceived as material and is usually identified with God or Nature. The Stoics also referred to the seminal logos ("logos spermatikos"), or the law of generation in the Universe, which was the principle of the active reason working in inanimate matter.

“Pierre Hadot describes the Logos like this: "The immanence of reason in matter. The reason that governs substance." David Sedley: "Stoic Chrysippus regarded pneuma as the vehicle of logos in structuring matter, both in animals and in the physical world. Margaret Graver: "incorporates within itself a set of structural principles which are linked to the structure and organization of the universe as a whole. The universe as a whole exhibits a structural and functional complexity like that of living things."... "The miraculous order which manifests itself in all of nature as well as in the world of ideas" - Albert Einstein.