From the Art of Making Money by PT Barnum (1880)

Among the maxims of the elder Rothschild was the apparently paradoxical: “Be cautious and bold.” This seems to be a contradiction in terms, but it is not, and there is great wisdom in the maxim. You must exercise your caution in laying your plans, but be bold in carrying them out.

People who are all caution never dare to take hold and be successful. Those who are all boldness are merely reckless, and must eventually fail.

A person may make $50 or $100,000 speculating in stocks at a single operation. But if this person has simple boldness without caution, it is mere chance, and what he or she gains today he or she will lose tomorrow.

The Rothschilds have another maxim: “Never have anything to do with an unlucky man or place.” This is to say, never have anything to do with a man or place that never succeeds. Although a man may look honest and intelligent, yet if he tries this or that thing and always fails it is on account of some fault or infirmity that you may not be able to discover but nevertheless must exist.

There is no such thing as luck. There never was a man who could go out in the morning and find a purse full of gold in the street today, another tomorrow, and so on, day after day. He may do so once in his life; but so far as mere luck is concerned, he is as liable to lose it as to find it.

If a man adopts the proper methods to be successful, luck will not stop him. If he does not succeed, there are reasons for it.

BE CAUTIOUS AND BOLD ... NEVER HAVE ANYTHING TO DO WITH AN UNLUCKY MAN OR PLACE