“A man is what he thinks all day long” is an old proverb by Ralph Waldo Emerson. It means that a man is mainly as he makes himself in mind.
Wealth and position do not bring true happiness or true power. The intellect has always ruled the world. ‘Minds are of celestial birth’. Man’s superiority consists in his intelligence.
It will be an interesting question for you to discuss who have contributed more to the growth of civilization - the great warriors or the great thinkers of the past. There is no doubt that the world is fast growing in knowledge.
He, therefore, is the truly great human whose intellect is ready to grapple with high and serious problems. Now, as the body is built of the food we take, so to the mind built of the thoughts we constantly entertain.
High thinking makes one noble.