Body comprises life and thought.
176. In almost every particular we find a sharp contrast between the Stoic conception of ‘body’ and the Epicurean ‘atom.’ The atom is extremely small and entirely unchangeable; ‘body’ is immensely large and in a high degree plastic. Atoms alternate with void; but ‘body’ spreads continuously throughout the entire universe; it can never be torn apart or show a gap[22]. Atoms move downwards in parallel straight lines; ‘body’ moves from the centre to the circumference, and thence returns to the centre. Two atoms can never occupy the same space; but ‘body’ everywhere moves through body, penetrating it and combining with it throughout its whole extent[23]. The atom is a convenient hypothesis within the range of modern physical and chemical science; the conception of ‘body’ gains force as we enter the region of biology. For life also is a movement which proceeds from a warm centre (and warmth is body rarefied), and extends towards a circumference which is in comparison gross and cold[24]. Going further, we find that ‘body’ and its functions are so interpreted as to provide a key to the activities of the human reason and will.
Tone or tension.
177. To the central conception of body are attached in the Stoic system various supplementary conceptions, which serve to bring into clearer view its nature and powers. Of these the most characteristic is that of ‘tone’ or ‘strain’ (τόνος, intentio). This term appears originally to have expressed muscular activity[25], and was next used by the Cynics to denote that active condition of the soul which is the true end of life; ‘no labour,’ said Diogenes, ‘is noble, unless its end is tone of soul[26].’ Although we cannot trace the term ‘tone’ directly to Zeno, we find that he explains sleep as a relaxation of the soul, substantially agreeing with later writers who call it a ‘relaxation of the sensory tone around the soul[27].’ With Cleanthes the word becomes fairly common, first in the ethical application, in which ‘tone’ is ‘a shock of fire, which if it be strong enough to stir the soul to fulfil its duties is called strength and force[28],’ and then in physics to explain the unceasing activity of the universe[29], personified by Hercules in Stoic allegorical theology[30]. In later writers tone becomes constantly associated with the ‘spirit’ or ‘thrill’ which explains both the unity and the movement of all things[31], so that ‘tone of spirit’ or ‘thrill-tone’ (πνευματικὸς τόνος, intentio spiritus) explains to us the operations of body and mind alike[32].
The seed power.
178. Body however is not only active but creative; there is inherent in it a power, which is that of the ‘seed’ (σπέρμα, semen), and which is most conspicuously illustrated in the seed of animals and plants. It is the characteristic of seed that from a small beginning it developes a great plan, and that this plan never changes[33]. This plan or purpose is named by the Stoics its ‘reason’ or ‘word’ (λόγος), and at this point Stoicism incorporates the doctrine of the ‘Word’ or universal reason with which it became acquainted through Heraclitus. The ‘Word’ or ‘seed-power’ (λόγος σπερματικός) of the universe is one; it is the primal fire in its work of creation; it is Zeus the Creator who moulds gross matter into the things that are to be[34]; it is wisdom which plies matter as it will[35]. But there are also in individual objects, animate and inanimate, indestructible seed-powers, countless in number, displayed alike in growth, procreation, and purpose[36]; these seed-powers are, as it were, spirits or deities, spread throughout the universe, everywhere shaping, peopling, designing, multiplying; they are activities of fiery spirit working through tension[37] in its highest development. But the seed-power of the universe comprehends in itself all the individual seed-powers; they are begotten of it, and shall in the end return to it. Thus in the whole work of creation and re-absorption[38] we see the work of one Zeus, one divine Word, one all-pervading spirit[39].
Cause.
179. Closely akin to the theory of ‘seed-powers’ and the Word is that of ‘cause’ (αἰτία, causa). Aristotle had already explained this term in connexion with cosmogony, laying down that, in order that a universe may come into being, three ‘causes’ are required; matter, without which nothing can be made; a workman, to make things; and the form or shape, which is imposed on every work as on a statue. To these may be added a fourth cause, the purpose of the work. Thus to produce a statue we need the bronze, the artist, the design, and the fee. Grammatically these causes may be expressed by the help of prepositions, as the ex quo, a quo, in quo and propter quod[40]. To this theory of multiple causes the Stoics oppose the doctrine of a single ‘first cause,’ the maker of the universe. This first cause can be none other than the primal creative fire in a new aspect; equally it is the creative Word.
It seems well to translate here in full the argument of Seneca on this point, for it stands almost alone as an example of his powers in continuous exposition:
The Stoic dogma is that there is one cause only, the maker. Aristotle holds that cause is threefold. ‘The first cause,’ he says, ‘is the material itself, for without it nothing can be made. The second cause is the maker. The third is the design, which is impressed on every single work as on a statue;’ this Aristotle calls the εἶδος. I will now explain what he means.