Teachings of Swami Vivekananda

There is a thorn in my finger and I use another to take the first one out, and when I have taken it out, I throw both of them aside. I have no necessity of keeping the second thorn, because both are thorns after all. So the bad tendencies are to be counteracted by the good ones, and the bad impressions on the mind should be removed by the fresh waves of good ones, until all that is evil almost disappears, or is subdued and held in control in a corner of the mind. But after that, the good tendencies have also to be conquered. Thus the 'attached' becomes the 'unattached.'

Class on Karma Yoga. New York, December 20, 1895. Complete Works, 1:55-56.