And it is this.
There are millions of people who suffer from irritability, want of self-control, loquacity, evil in many forms, or nerves, who would fain control themselves and stop it all.

Moralists think that for this it is enough to convince their reason.

But this rarely avails.

A man may _know_ that he is wrong, yet _not_ be able to reform.

Now, what he wants is to have his attention fixed long enough to form a new habit.
Find out how this can be done, and it may in many cases be the simplest and most mechanical thing in the world to cure him.