An interesting passage may be quoted from [393] Plutarch on the Stoic doctrine of knowledge: "The Stoics maintain," he says, "that when a human being is born, he has the governing part of his soul like a sheet of paper ready prepared for the reception of writing, and on this the soul inscribes in succession its various ideas. The first form of the writing is produced through the senses. When we perceive, for example, {232} a white object, the recollection remains when the object is gone. And when many similar recollections have accumulated, we have what is called experience. Besides the ideas which we get in this natural and quite undesigned way, there are other ideas which we get through teaching and information. In the strict sense only these latter ought to be called ideas; the former should rather be called perceptions. Now the rational faculty, in virtue of which we are called reasoning beings, is developed out of, or over and beyond, the mass of perceptions, in the second seven years' period of life. In fact a thought may be defined as a kind of mental image, such as a rational animal alone is capable of having."
Thus there are various gradations of mental apprehensions; first, those of sensible qualities obtained through the action of the objects and the assent of the perceiving subject, as already described; then by experience, by comparison, by analogy, by the combinations of the reasoning faculty, further and more general notions are arrived at, and conclusions formed, as, for example, that the gods exist and exercise a providential care over the world. By this faculty also the wise man ascends to the apprehension of the good and true.
The physics of the Stoics started from the fundamental [398] proposition that in the universe of things there were two elements—the active and the passive. {233} The latter was Matter or unqualified existence; the former was the reason or qualifying element in Matter, that is, God, who being eternal, is the fashioner of every individual thing throughout the universe of matter. God is One; He is Reason, and Fate, and Zeus. In fact all the gods are only various representations of His faculties and powers. He being from the beginning of things by Himself, turneth all existence through air to water. And even as the genital seed is enclosed in the semen, so also was the seed of the world concealed in the water, making its matter apt for the further birth of things; then first it brought into being the four elements—fire, water, air, earth. For there was a finer fire or air which was the moving spirit of things; later and lower than this were the material elements of fire and air. It follows that the universe of things is threefold; there is first God Himself, the source of all character and individuality, who is indestructible and eternal, the fashioner of all things, who in certain cycles of ages gathers up all things into Himself, and then out of Himself brings them again to birth; there is the matter of the universe whereon God works; and thirdly, there is the union of the two. Thus the world is governed by reason and forethought, and this reason extends through every part, even as the soul or life extends to every part of us. The universe therefore is a living thing, having a {234} soul or reason in it. This soul or reason one teacher likened to the air, another to the sky, another to the sun. For the soul of nature is, as it were, a finer air or fire, having a power of creation in it, and moving in an ordered way to the production of things.
[399]
The universe is one and of limited extension, being spherical in form, for this is the form which best adapts itself to movement. Outside this universe is infinite bodiless space; but within the universe there is no empty part; all is continuous and united, as is proved by the harmony of relation which exists between the heavenly bodies and those upon the earth. The world as such is destructible, for its parts are subject to change and to decay; yet is this change or destruction only in respect of the qualities imposed upon it from time to time by the Reason inherent in it; the mere unqualified Matter remains indestructible.
[408]
In the universe evil of necessity exists; for evil being the opposite of good, where no evil is there no good can be. For just as in a comedy there are absurdities, which are in themselves bad, but yet add a certain attraction to the poem as a whole, so also one may blame evil regarded in itself, yet for the whole it is not without its use. So also God is the cause of death equally with birth; for even as cities when the inhabitants have multiplied overmuch, {235} remove their superfluous members by colonisation or by war, so also is God a cause of destruction. In man in like manner good cannot exist save with evil; for wisdom being a knowledge of good and evil, remove the evil and wisdom itself goes. Disease and other natural evils, when looked at in the light of their effects, are means not of evil but of good; there is throughout the universe a balance and interrelation of good and evil. Not that God hath in Himself any evil; the law is not the cause of lawlessness, nor God Himself responsible for any violation of right.
[404]
The Stoics indulged in a strange fancy that the world reverted after a mighty cycle of years in all its parts to the same form and structure which it possessed at the beginning, so that there would be once more a Socrates, a Plato, and all the men that had lived, each with the same friends and fellow-citizens, the same experiences, and the same endeavours. At the termination of each cycle there was a burning up of all things, and thereafter a renewal of the great round of life.
[408]