The process of experience has been by Plato called Anamnesis or Recollection. But Recollection is not always an easy, and never a merely passive, process; and sometimes the forgetfulness seems so deep that no extraneous stimulus can at all move it. We have seen already one of these stimuli which rouse the sleeping sense--the mystery of numbers: and there are many others. But, we have also learned, that in the psychical sphere items of memory are not, as reckless fancy puts it, stored up in compartments, sorted and arranged, ready to be pulled out. The process of recollection is a complicated affair: an affair of give and take, of comparison and selection and rejection, of construction and reconstruction. You cannot haul up ready-made memories from the mine. And this perhaps was sometimes forgotten by Plato; it certainly has been by more than one of his commentators. You may, no doubt, call up ideas from the vasty deep: but they come by laws and principles of their own. Even when they come, which they sometimes do unexpectedly, they come as an echo of the calling mind. Recollection involves intellectual process: as Kant said, the synthesis of imagination reposes upon the synthesis in the concept. Yet--and this is the point which Plato's title of _Anamnesis_ accentuates--unless 'the soul had been such as to be affected in this way' (the words are those of Aristotle), unless the soul had been implicitly intellectual in tone and faculty, it would not have grasped the presented universe under the categories which it uses. There is, says Aristotle, in the barest act of sensation a congenital power of judgment; there is, says Plato, an eye of the soul--a natural virtue of intelligence, which can never be put into it, and must always be presupposed in any theory of its processes.