We ask each student of this book to acquaint himself with the general idea of the working features of the law of association as given in this chapter for the reason that much of the instruction to be given under the head of the several phases and classes of memory is based upon an application of the Law of Association, in connection with the law of Attention. These fundamental principles should be clearly grasped before one proceeds to the details of practice and exercise. One should know not only "how" to use the mind and memory in certain ways, but also "why" it is to be used in that particular way. By understanding the "reason of it," one is better able to follow out the directions. CHAPTER VIII. PHASES OF MEMORY. One of the first things apt to be noticed by the student of memory is the fact that there are several different phases of the manifestation of memory. That is to say, that there are several general classes into which the phenomena of memory may be grouped. And accordingly we find some persons quite highly developed in certain phases of memory, and quite deficient in others. If there were but one phase or class of memory, then a person who had developed his memory along any particular line would have at the same time developed it equally along all the other lines. But this is far from being the true state of affairs. We find men who are quite proficient in recalling the impression of faces, while they find it very difficult to recall the names of the persons whose faces they remember. Others can remember faces, and not names. Others have an excellent recollection of localities, while others are constantly losing themselves. Others remember dates, prices, numbers, and figures generally, while deficient in other forms of recollection. Others remember tales, incidents, anecdotes etc., while forgetting other things. And so on, each person being apt to possess a memory good in some phases, while deficient in others. The phases of memory may be divided into two general classes, namely (1) Memory of Sense Impressions; and (2) Memory of Ideas. This classification is somewhat arbitrary, for the reason that sense impressions develop into ideas, and ideas are composed to a considerable extent of sense impressions, but in a general way the classification serves its purpose, which is the grouping together of certain phases of the phenomena of memory.