The ancient Stoics believed that everything that exists is composed of matter and only bodies exist. Bodies can cause change in other bodies. Four things were said not to exist as independent entities, but to subsist (they are depended on things that exist), these four incorporeal things are:
Sayables (the meaning of something said)
The Stoics were monists, they believed that the universe was a cohesive singular whole. However things that exist could be active or passive. They could cause change or have change inflected upon them. These things were blended together creating our physical universe. Pneuma (breath) was an active organizing principle of the Cosmos that existed in all things. The amount of Tension that Pneuma exerted on a particular object could give it various properties including life, intelligence and rational judgement.
To learn about this topic in greater detail, I highly recommend Stoicism by Dr. John Sellars.