In the western hemisphere, the word “Yoga” usually have the association of the practice of physical exercise through getting oneself into positions (Asanas) that strengthen the muscles and stretch the body. Yet it is a relatively known fact that yogic philosophy exists, and is a much wider discipline than asana practice - which is a but a subset of Hatha yoga, the branch of yoga dealing with physical techniques (Asanas, Shatkarmas - cleaning rituals, Pranayama - breathing exercises, and more).
The main road to spiritual growth in yogic philosophy as it is usually understood is founded on meditative states. According to the author, Swami Vivekananda, there are other paths to achieving the same destination. Three selected ones are described in his books on yogic philosophy - Bhakti Yoga, Jnana Yoga, and the subject of this review - Karma Yoga. (Another book of the series is Raja Yoga, but this fourth one does deal with meditative technique at its core).
And what destination is it, that yoga aspires to? It is freedom. Freedom of the soul, freedom from suffering, and union with your true being. The term योग “Yoga” itself comes from the Sanskrit root युज “Yuj”, meaning ”to join”, “to yoke” or “to unite”.
In his book “Karma Yoga”, a less known path is described. This is the path of spiritual growth through selfless, detached performance of one’s duties. In common terms, remaining free and clear headed throughout work and duty fulfilment.

What is duty? According to Vivekananda, it is performing what is expected of one - what one expects of himself - according to his culture and position in life. For the family man it is to provide, for the monk it is to worship and to meditate, for the teacher it is to educate, and for the robber - to rob.
Karma yoga does not seek to moralize us and tell us what it is that is right to do. Generally, the ethical approach of Vivekananda is very different to the typical western philosophical approach. Making the world a better place is not the direct goal. Vivekananda often claims that such an attempt is presumptuous and unrealistic - the world is as it is, and will not change (more on that later).
There are stages to this process of freeing oneself through work or duty. At first, one is not used to work, and must get used to it for whatever reasons motivate him personally, whether it is his own well being, wealth, joy or mere survival.
In the second stage, once one is accustomed to work, one is encouraged to work selflessly for the fulfillment of these things he believes his duty to be and to be content with the fruits of his work, through that view point. This will lead to a process where the habits of ones mind are to think selfless and good (according to ones viewpoint. The robber was mentioned for a reason) thoughts and not evil or selfish ones - this is a self-encouraging process.
Once one is accustomed enough to selfless thoughts and motives, perturbations in the environment and the chaos of life will still leave him thinking such thoughts and performing his duties as such, which will reinforce these patterns - a good action has a good effect on you, a bad action has a bad effect, and good effects on you and your soul makes you more likely to perform additional good and selfless actions.
Yet this is, according to him, just another step in the process. Once one is accustomed to performing his duty for good reasons, one is not free yet. The next step is becoming detached from the fruits and results of one’s work. Realizing that the good action itself is the thing to do, regardless of its impact of the world.
This is weakness to think that some one depends on me, and I can do good to somebody. This pride is the mother of all our attachment, and through this attachment comes all our pain. We must inform our minds that no one in this universe depends upon us; not one beggar depends on our charity; not one soul on our kindness; not one on our help.
So if not for yourself, nor world nor for others, what is it one is working for? One is working for work sake itself. you are to learn to control your mind, do selfless deeds without caring at all about the selfless results. In a fable, the author describes the required state of mind as similar to this of a nurse when nursing someones children, even if they are your own.
The nurse will take your baby and fondle it and play with it and behave as gently as if it were her own child, but as soon as you give her notice she is ready to start off with her baggage from the house. Everything is forgotten; it would not give the ordinary nurse the least pang to leave your children and take up other children. Even so be with your own. You are the nurse, and, if you believe in God, believe that these are all His.
Once that state of selfless and detached work has been fully achieved, one will be both most efficient, and, finally - free.