Seneca and some friends have a debate about the prime cause of the universe. It seems his friends perhaps tilt towards the Platonic and Aristotelian perspectives. Seneca does a fine job summarizing the differing perspectives.
For the Stoics, the prime cause is Nature/Reason/Cosmos/the Universe. And to be even more specific, it is pneuma that is the prime mover and cause of all actions in the universe.
two things in the universe which are the source of everything, – namely, cause and matter. Matter lies sluggish, a substance ready for any use, but sure to remain unemployed if no one sets it in motion. Cause, however, by which we mean reason, moulds matter and turns it in whatever direction it will, producing thereby various concrete results.
The Stoics believe in one cause only, – the maker.
Elsewhere, Aetius states,
The Stoics made god out to be intelligent, a designing fire which methodically proceeds towards creation of the world, and encompasses all the seminal principles according to which everything comes about according to fate, (2) and a breath pervading the whole world, which takes on different names owing to the alterations of the matter through which it passes (The Hellenistic Philosophers, Long, Sedley, p. 274-275).
After contrasting the Stoic view with the Platonic and Aristotelian, the question becomes very deeply philosophical.
Do you ask what God's purpose is?
Seneca states that God's purpose is goodness.
Elsewhere, I've written about what I've learned in the College of Stoic Philosophers, in which I noted others' theories that God not only has infinite potential, but God's purpose is to experience all that potential (see the God, Determinism and Free Will section of my essay on Stoic Physics).
Seneca then addresses a very practical question:
"What pleasure do you get from wasting your time on these problems, which relieve you of none of your emotions, rout none of your desires?"
His response to the question he poses, is worth reading in its entirety.
So far as I am concerned, I treat and discuss them as matters which contribute greatly toward calming the spirit, and I search myself first, and then the world about me. And not even now am I, as you think, wasting my time. For all these questions, provided that they be not chopped up and torn apart into such unprofitable refinements, elevate and lighten the soul, which is weighted down by a heavy burden and desires to be freed and to return to the elements of which it was once a part. For this body of ours is a weight upon the soul and its penance; as the load presses down the soul is crushed and is in bondage, unless philosophy has come to its assistance and has bid it take fresh courage by contemplating the universe, and has turned it from things earthly to things divine. There it has its liberty, there it can roam abroad; meantime it escapes the custody in which it is bound, and renews its life in heaven.
Marcus Aurelius, similarly took a metaphysical flight through the cosmos, perhaps too, contemplating God's purpose.
the rational soul traverses the whole universe and its surrounding void, explores the shape of it, stretches into the infinity of time, encompasses and comprehends the periodic regeneration of the Whole (Meditations 11.1).
And lastly, I recently came across this passage by Pierre Hadot in The Present Alone is Our Happiness where he said,
Things changed at the time of my adolescence. Indeed, I have long had the impression of having been in the world only from the time I became an adolescent. I will always regret having thrown away - out of Christian humility - my first handwritten notes that were an echo of the birth of my personality, for it is very difficult for me now to rediscover the psychological content of the overwhelming discoveries I made then. I do remember their context. One happened on rue Ruinart, on the route I took home to my parents' house every day from the Petit Seminaire. Night had fallen. The stars were shining in an immense sky; one could still see them at the time. Another took place in a room of our house. In both cases I was filled with an anxiety that was both terrifying and delicious, provoked by the sentiment of the presence of the world, or of the Whole, and of me in that world. In fact, I was incapable of formulating my experience, but after the fact I felt that it might correspond to questions such as What am I? Why am I here? What is this world I am in? I experienced a sentiment of strangeness, of astonishment, and of wonder at being there. At the same time I had the sentiment of being immersed in the world, of being a part of it, the world extending from the smallest blade of grass to the stars. This world was present to me, intensely present. Much later I would discover that this awareness of my immersion in the world, this impression of belonging to the Whole, was what Romain Rolland called the "oceanic feeling." I think I have been a philosopher since that time, if by philosophy one understands this awareness of existence, of being-in-the-world (p. 5-6).
In a sense, it seems that Seneca, Aurelius and Hadot speak of out-of-body experiences. Seneca reminds us that our body is a form of slavery and that we ought to spend our experience in the higher sphere rather the bodily.
The wise man, the seeker after wisdom, is bound closely, indeed, to his body, but he is an absentee so far as his better self is concerned, and he concentrates his thoughts upon lofty things. Bound, so to speak, to his oath of allegiance, he regards the period of life as his term of service. He is so trained that he neither loves nor hates life; he endures a mortal lot, although he knows that an ampler lot is in store for him.
Seneca then rhetorically asks thirteen deep questions, to demonstrate to Lucilius, that questions - philosophical questions - can have a freeing effect on our minds and that we are not slaves to our bodies and that our minds can contemplate and discuss such lofty subjects.
this freedom will be greatly helped by the contemplation of which we were just speaking.
He then evokes the Scala naturae in the context of God and humans.
All things are made up of matter and of God; God controls matter, which encompasses him and follows him as its guide and leader. And that which creates, in other words, God, is more powerful and precious than matter, which is acted upon by God. God's place in the universe corresponds to the soul's relation to man. World-matter corresponds to our mortal body; therefore let the lower serve the higher. Let us be brave in the face of hazards. Let us not fear wrongs, or wounds, or bonds, or poverty.
And the very essence of us is pneuma as displayed by our hegemonikon. While we are a part of the Cosmos and the Whole, we nevertheless have autonomy in how we display that which is unique to us. While the indifferents in our life (hazards, fears, wrongs, wounds, bonds, poverty, riches, etc.) do not represent us entirely, it is our unique response to these things which define us. In our space of choice, is how we exercise our autonomy, creativity, personality and virtue: our arete.