Book 7
1.50
There is a difference between the process and the outcome of presentation. The latter is a semblance in the mind such as may occur in sleep, while the former is the act of imprinting something on the soul, that is a process of change, as is set forth by Chrysippus in the second book of his treatise Of the Soul (De anima). For, says he, we must not take impression in the literal sense of the stamp of a seal, because it is impossible to suppose that a number of such impressions should be in one and the same spot at one and the same time. The presentation meant is that which comes from a real object, agrees with that object, and has been stamped, imprinted and pressed seal-fashion on the soul, as would not be the case if it came from an unreal object.
1.51
According to them some presentations are data of sense and others are not: the former are the impressions conveyed through one or more sense-organs; while the latter, which are not data of sense, are those received through the mind itself, as is the case with incorporeal things and all the other presentations which are received by reason. Of sensuous impressions some are from real objects and are accompanied by yielding and assent on our part. But there are also presentations that are appearances and no more, purporting, as it were, to come from real objects.
1.51
Another division of presentations is into rational and irrational, the former being those of rational creatures, the latter those of the irrational. Those which are rational are processes of thought, while those which are irrational have no name. Again, some of our impressions are scientific, others unscientific: at all events a statue is viewed in a totally different way by the trained eye of a sculptor and by an ordinary man.
