Seek thou refuge in wisdom. Wretched are they whose motive is the reward. Therefore, devote thyself to yoga.
Yoga is skill in action.
Before performing any action, look to buddhi for orders. This is buddhi yoga. History extols the great deeds of men of extraordinary skill who have shaped nations. History is concerned with social values, not with inner wisdom. When thousands of tons of earth are crushed, you get a small but most precious diamond.