to things, but with difficulty to words about things. To maintain
attention for an hour or so, while sitting, is a task, and there
develops a tendency either to a hypnoidal state in which the mind
follows uncritically, or to a restless uneasiness with wandering
mind and fatigue of body. A demonstration, on the other hand, a
laboratory experiment with short, personal instruction, a bodily
contact with the problem calls into play interest, enthusiasm,
curiosity, motor images, the use of the hands, and is THE method
of teaching.

There are at present excellent psychological methods of testing
out the memory capacity. Every one engaged in any responsible
work, or troubled about his memory, should be so tested. While
there are other qualities of mind of great importance, memory is
basic, and no one can really understand himself who is in doubt
about his memory. In such diseases as neurasthenia one of the
commonest complaints is the "loss of memory," which greatly
troubles the patient. As a matter of fact, what is impaired is
interest and attention, and when the patient realizes this he is
usually quite relieved. The man who has a poor memory may become
very successful if he develops systems of recording, filing,
indexing, but his possibilities of knowledge are greatly reduced
by his defect.[1]

[1] It is the growth of the subject matter of knowledge that
makes necessary the elaborate systems of indexing, etc., now so
important. It is as much as man can do to follow the places where
the men work, let alone what they are doing. This growth of
knowledge is getting to be an extra-human phenomenon. Of this
Graham Wallas has written entertainingly.