Henry Hazlitt said this quote

The dilemma is this. In the modern world knowledge has been growing so fast and so enormously, in almost every field, that the probabilities are immensely against anybody, no matter how innately clever, being able to make a contribution in any one field unless he devotes all his time to it for years. If he tries to be the Rounded Universal Man, like Leonardo da Vinci, or to take all knowledge for his province, like Francis Bacon, he is most likely to become a mere dilettante and dabbler. But if he becomes too specialized, he is apt to become narrow and lopsided, ignorant on every subject but his own, and perhaps dull and sterile even on that because he lacks perspective and vision and has missed the cross-fertilization of ideas that can come from knowing something of other subjects.

~ Henry Hazlitt

There is a strange idea abroad, held by all monetary cranks, that credit is something a banker gives to a man. Credit, on the contrary, is something a man already has. He has it, perhaps, because he already has marketable assets of a greater cash value than the loan for which he is asking. Or he has it because his character and past record have earned it. He brings it into the bank with him. That is why the banker makes him the loan. The banker is not giving something for nothing.

~ Henry Hazlitt

A man with a scant vocabulary will almost certainly be a weak thinker. The richer and more copious one's vocabulary and the greater one's awareness of fine distinctions and subtle nuances of meaning, the more fertile and precise is likely to be one's thinking. Knowledge of things and knowledge of the words for them grow together. If you do not know the words, you can hardly know the thing.

~ Henry Hazlitt

The only way we could remember would be by constant re-reading, for knowledge unused tends to drop out of mind. Knowledge used does not need to be remembered; practice forms habits and habits make memory unnecessary. The rule is nothing; the application is everything.

~ Henry Hazlitt