III.
The Stoics took Plato’s figure of the wax almost literally! They held that the mind is originally atabula rasa. Sensations are the first writing upon this tablet. The object of sensation makes an impression upon the perceiving subject, as the seal impresses the wax. Memory depends upon this impression. This was the view of Zeno. Chrysippus found difficulties in such a crude materialistic theory. How could the mind receive and retain at the same time a number of different and partlyincompatible impressions? Accordingly he replaced this view by the theory that the sense impression consists inaqualitative change (ἀλλοίωσις) of the passively receiving organ, the soul.[28]The presentation (φαντασία) is a state of the soul. The relation of memory to the general theory of knowledge with the Stoics was briefly as follows:—The lowest act of the soul is mere perception (αἴσθησις); the next is presentation (φαντασία), which adds conscious observation, its function beingto make a first test of the truth of the material furnished by sense. If perception has offered a true picture of the external object, this presenting activity of the mind becomes so intensive that the understanding is brought into action. The understanding or judgment approves or disapproves the presentations. If it approves, there arises the empirical fact, which bears upon it the mark of truth. These facts memory stores up. By combination of the separate facts empirical concepts are formed which make up the treasure of memory or experience.[29]
The psychology of Epicurus and the other atomists was a simple kind of mechanical sensationalism.Eidolaor images from external objects enter the soul through the sense organs. The mind stores up a great multitude of theseeidola. Whenever we call up a picture of memory or of the imagination, we turn the attention to one of these images. Thus the mind sees in the same way that the eye does, with this difference, that it perceives much thinner eidola.[30]
Cicero and Quintilian both dwell upon the importance of memory; and both seem to adopt the common theory of the time, that impressions are stamped on the mind as the signets are marked on wax. They are especially concerned, however, with principles relating to the exercise of memory; and they give instructions for mnemonic aids in oratory. Cicero lays special stress upon order as an aid to memory; and as sight is the most acute of the senses, those things are best remembered which are visualized by the imagination. In accordance with the ancient mnemonic systems he wouldhave these imagined forms localized. The advice of Quintilian in respect to memory is especially sensible. According to him, nothing can take the place of exercise and labor. Next in importance is the division and arrangement of one’s subject. He notices also the importance of good health; and says that for slow minds an interval of rest is a good thing, though he seems to be uncertain whether the advantage is due to the rest, or whether it gives reminiscence time to mature.[31]