Active and passive matter

According to the Stoics,
there is a sacred connection that runs through the universe.

To truly grasp the concepts of immanence or determinism from a Stoic perspective, we need to let go of our tendency to view the world in purely material or mechanical terms. The Stoics saw the universe as a living whole, structured, rational, and alive.
At the foundation of this cosmos,
two fundamental principles work together to bring reality into being:
the active principle
and the passive principle.

The passive principle, first of all, refers to raw matter, that from which everything is made. It is undetermined substance, inert in itself, unable to structure or transform on its own. By itself, this principle cannot produce life, order, or movement. It is pure potentiality, the receptive element.

The active principle, on the other hand, is what shapes, organizes, and animates. It penetrates matter and gives it structure, form, and dynamism. For the Stoics, this active principle is the Logos: divine reason, the rational breath (pneuma) that flows through all things and brings the world into order. It is at once cause, intelligence, energy, and coherence. It is what turns a mere heap of matter into a living being, a tree, a planet, a human.

Look at a candle, its wax represents the passive principle. It is the matter, the raw and potential substance. On its own, it is inert, incapable of action or transformation. The flame, on the other hand, embodies the active principle. It is the energy, the force that transforms the wax, giving it form, heat, light, and motion.

Or take the earth. The soil that receives the seed, with its moisture, minerals, and stability, represents the passive principle. It is the receptive matter, the foundation upon which something can emerge.
The germinating force within the seed itself is the active principle. It is that invisible impulse, that vegetal logos, which urges the seed to unfold, to become root, stem, and eventually, tree.

Or again: the block of marble is the passive principle — raw matter, silent, full of potential but without form or direction. The sculptor’s hand, guided by an inner vision, is the active principle, it carves, shapes, and brings order.

In this view, then,
nothing exists independently of these two principles, which gives the world a deeply unified character. It rejects any notion of matter as “base” or negligible, and of spirit as “pure” or superior. On the contrary, one cannot exist without the other. Matter is necessary, but it is reason that makes it alive, intelligible, and harmonious. This duality is not a dualism of separation, as found in certain philosophical or religious traditions, but a dual-aspect of one and the same cosmic reality: nature. Here lies an important distinction. Many religious traditions or philosophical schools have, over time, established a hierarchy between the two: on one side, matter, seen as changeable, corruptible, tied to desire and death, was often reduced to an obstacle or an illusion; and on the other, spirit, regarded as pure, unmoving, eternal, was seen as the only part worthy of salvation, destined to return to a higher spiritual realm.

The Stoics, for their part, reject this opposition.
They do not reject matter, nor the body, nor the world of the senses.
For them, the entire cosmos is both body and soul,
all of reality is the result of the interplay between the two: matter and reason, the passive principle and the active one. Can’t you see it for yourself, every day, in what is most intimate to you, yourself? You too are made of a body (matter) and a rational soul (the active principle within us), capable of judgment, choice, and direction, aren’t you?