Simply put, Plotinus’ conception of the universe is an ensouled body. It is soul, because it is self-containing and remaining still; it is body, because the natural movement of body is in a straight line, but when it is contained by the power of the soul, it moves in a circle (geodesic), always remaining in possession of the soul. The circular or spherical motion combines both the stillness of the soul and the straight-line movement of the body. The Soul is universal, therefore each part of the universe is also a universe in itself.
The stars have “not only their spherical motion with whole universe but also individual motions around its own centre”. The Solar System is a microcosm of the universe, if we consider the revolution of the Earth around the Sun and its self rotation, and in turn the revolution of the Moon around the Earth and its synchronous rotation.
“Atoms do not exist at all, for every body is altogether divisible”.
Atom is derived from the Greek word meaning literally undivided or uncuttable. The existence of atoms was first proposed by Democritus and accepted by Epicureans. Plotinus refuted the idea of indivisible atoms for two main reasons among others. Firstly, the corporeity of bodies are formative principles belonging to intellect not matter, in other words, they are forms impressed on matter. So every individual body can be destroyed when the form is separated from the matter. Secondly, if the atoms are indivisible, it would impose limitations on the power of the Maker to create all things from these discontinuous and indivisible atoms, like a potter having to work with potsherds that cannot be molded into anything else.
Plotinus proposed matter in place of atom. Matter is the unlimited, potential receptacle of forms; it is without size, without quality or quantity, and completely undefined. However, the existence of matter cannot be proven by the senses, because it is incorporeal. How do we know that matter exists then? By reasoning. It follows logically from a synthesis of Platonic conception of Form and Aristotle’s conception of potentiality and actuality, activity and receptivity.
It was not until early 19th century that modern atomic theory was formulated, in the early 20th century physicists discovered subatomic particles, and they have been dividing and discovering more elementary particles ever since.