The giants of the race have been men of concentration, who have struck sledge-hammer blows in one place until they have accomplished their purpose. The successful men of today are men of one overmastering idea, one unwavering aim, men of single and intense purpose.
Orison Swett Marden (2015). “An Iron Will, He Can Who Thinks He Can & Pushing To The Front (Wisdom & Empowerment Series): How to Achieve Self-Reliance Which Leads to Vigorous Self-Faith, Personal Growth & Success”, p.288, e-artnow