This section is from the book "Applications of Psychology to the Problems of Personal and Business Efficiency", by Warren Hilton. Also available from Amazon: Psychology and Achievement - Applied Psychology 12 Volume Set.
YOU have learned of the sense-perceptive and judicial processes by which your mind acquires its knowledge of the outside world. You come now to a study of the phenomenon of memory, the instrument by which your mind retains and makes use of its knowledge, the agency that has power to resurrect the buried past or power to enfold us in a Paradise of dreams more perfect than reality.
In the broadest sense, memory is the faculty of the mind by which we (1) retain, (2) recall, (3) picture to the mind's eye, and (4) recognize past experiences.
Memory involves, therefore, four elements, Retention, Recall, Imagination and Recognition.