5 Things You Must Know about Stoic Physics

Per wikipedia:

Stoic physics is the natural philosophy adopted by the Stoic philosophers to explain the natural processes at work in the universe. According to the Stoics, the cosmos is a single pantheistic god, one which is rational and creative, and which is the basis of everything which exists. The nature of the world is one of unceasing change, driven by the active part or reason (logos) of God which pervades all things. The active substance of the world is a ‘breath’, or pneuma, which provides form and motion to matter, and is the origin of the elements, life, and human rationality.

Wikipedia contributors. (2020, October 29). Stoic physics. In Wikipedia, The Free Encyclopedia. Retrieved 00:54, November 2, 2020, from https://en.wikipedia.org/w/index.php?title=Stoic_physics&oldid=986115379

Here are 5 things you must know about Stoic physics.

1. The Stoics physics has three key features: monism, materialism, and dynamism. The Stoics believed the universe is monistic. They thought that universe was one whole complete and cohesive unit with all the parts interacting and having an affinity for another. The Stoics thought that the universe was composed only of a material substance and even abstract things like justice and wisdom were corporeal. The Stoics did acknowledge the reality of things like void, space, and time but they thought they subsisted on material bodies and did not exist on their own. Stoic physics was also dynamic. The Stoic split matter into two different sorts, active matter and passive matter. There is matter that is capable of acting upon or is acted upon.
   
2. The Stoics once held that the active principle of the universe (aka God) is a creative fire. But later accounts describe the active principle as pneuma (or breath). Pneuma is believed to be coextensive with all passive matter (ousia). Pneuma gives stable physical properties to objects.
   
3. The Stoics saw the cosmos as a finite spherical being which is embedded in an infinite void, with fixed stars, sun, and planets orbiting the Earth. The Stoics believed that the cosmos would expand or contract in volume during its cycles.
   
4. The Stoics, going against Aristotle, rejected three of the four types of causes and stuck with efficient causation, which is the cause and effect relationship modern science uses to explain phenomena. Aristotle believed that all matter had a final cause to which things aspired to be. The Stoics, disagreeing with Aristotle, believed that the reason of things, the logos, was deeply interspersed with all inactive matter, helping matter generate new objects and new life. The universe is thought to be rational and alive but not in a modern biology textbook definition of alive.
   
5. The Stoics believed and still do believe that determinism is true, that every happening has a cause. The Stoics also believe that every rational human has the capacity for self-control or autonomy. People bring up free will but it’s actually a red herring because the Stoics weren’t concerned with free will the way people define it today. Finally, the Stoics believed only in efficient causation and only materially or physically existing things. You could say that the Stoics got a lot right regarding the cosmos. You could also say they got everything right (and making a case for that seems plausible).