Sentence:  Throughout my life ... I have been fortified in the conclusion that it is much more important for a young man to be a worker, even though not brilliant, than to be brilliant and not a worker. As one looks back at some companions who attended lectures, and follows the records of their lives, one is strengthened in this belief because the facts show that the steady <WSD>plodders</WSD> have gone further than have some of those brilliant lads of other days. 
Meaning of the word marked with <WSD> tags:  A person who works slowly, making a great effort with little result; a person who studies laboriously.