A Treatise On The Soul by Tertullian
Chapter XIV.--The Soul Variously Divided by the Philosophers; This Division is Not a Material Dissection.
Being thus single, simple, and entire in itself, it is as incapable of being composed and put together from external constituents, as it is of being divided in and of itself, inasmuch as it is indissoluble. For if it had been possible to construct it and to destroy it, it would no longer be immortal. Since, however, it is not mortal, it is also incapable of dissolution and division. Now, to be divided means to be dissolved, and to be dissolved means to die. Yet (philosophers) have divided the soul into parts: Plato, for instance, into two; Zeno into three; Panætius, into five or six; Soranus, into seven; Chrysippus, into as many as eight; and Apollophanes, into as many as nine; whilst certain of the Stoics have found as many as twelve parts in the soul. Posidonius makes even two more than these: he starts with two leading faculties of the soul, -- the directing faculty, which they designate hegemonikon; and the rational faculty, which they call logikon, -- and ultimately subdivided these into seventeen parts. Thus variously is the soul dissected by the different schools. Such divisions, however, ought not to be regarded so much as parts of the soul, as powers, or faculties, or operations thereof, even as Aristotle himself has regarded some of them as being. For they are not portions or organic parts of the soul's substance, but functions of the soul -- such as those of motion, of action, of thought, and whatsoever others they divide in this manner; such, likewise, as the five senses themselves, so well known to all -- seeing, hearing, tasting, touching, smelling. Now, although they have allotted to the whole of these respectively certain parts of the body as their special domiciles, it does not from that circumstance follow that a like distribution will be suitable to the sections of the soul; for even the body itself would not admit of such a partition as they would have the soul undergo. But of the whole number of the limbs one body is made up, so that the arrangement is rather a concretion than a division. Look at that very wonderful piece of organic mechanism by Archimedes, -- I mean his hydraulic organ, with its many limbs, parts, bands, passages for the notes, outlets for their sounds, combinations for their harmony, and the array of its pipes; but yet the whole of these details constitute only one instrument. In like manner the wind, which breathes throughout this organ at the impulse of the hydraulic engine, is not divided into separate portions from the fact of its dispersion through the instrument to make it play: it is whole and entire in its substance, although divided in its operation. This example is not remote from (the illustration) of Strato, and Ænesidemus, and Heraclitus: for these philosophers maintain the unity of the soul, as diffused over the entire body, and yet in every part the same. Precisely like the wind blown in the pipes throughout the organ, the soul displays its energies in various ways by means of the senses, being not indeed divided, but rather distributed in natural order. Now, under what designations these energies are to be known, and by what divisions of themselves they are to be classified, and to what special offices and functions in the body they are to be severally confined, the physicians and the philosophers must consider and decide: for ourselves, a few remarks only will be proper.