t of this. The habit of
using a "pony," for example, arises when one permits oneself to depend
upon a group of English words in translating from a foreign language.

Nerve pathways should then be guarded with respect to _what_ enters.
They should also be guarded with respect to the _way_ things enter.
Remember, as the first pathway is cut, subsequent nervous currents will
be directed. Consequently if you make a wrong pathway, you will have
trouble undoing it.

Another maxim which will obviously prevent undesirable pathways is, go
slowly at first. This is an important principle in all learning. If,
when trying to learn the date 1453, you carelessly impress it first as
1435, you are likely to have trouble ever after in remembering which is
right, 1453 or 1435. As you value your intellectual salvation, then, go
slowly in making the first impression and be sure it is right. The next
rule is: Guard the exits of the nervous currents. That is, watch the
movements you make in response to impressions and ideas. This is
necessary because the nervous current pushes on past obstructions,
through areas in the brain, until it ends in some form of movement, and
in finding the way out, it seeks those pathways that have been most
frequently travelled. In study, it usually takes the form of movements
of speech or writing. You will need to guard this part of the process
just as you did the incoming pathway You must see that the movement is
made which you wish to build into a habit. In learning the
pronunciation of a foreign word, for example, see that your first
pronunciation of it is absolutely right. When learning to typewrite
see that you always hit the right key during the early trials. The
point of exit of a nervous current is the point also where precautions
are to be taken in developing good form. The path should be the
shortest possible, involving only those muscles that are absolutely
necessary. This makes for economy of effort.

The third general principle to be kept in mind is that habits are most
easily formed in youth, for this is the period when nerve tissue is
most easily impressed and modified. With respect to habit formation,
then, you see that youth is the time when emphasis should be laid upon
the formation of as many useful habits as possible. The world
recognizes this to some extent and society is so organized that the
youth of the race are given leisure and protection so that they may
form useful habits. The world