Coin collecting of investment, the principle of "caveat emptor" applies and study is recommended before buying. Likewise, as with most collectibles, a coin collection does not produce income until it is sold, and may even incur costs (for example, the cost of safe deposit box storage) in the interim. Coin hoarders may be similar to investors in the sense that they accumulate coins for potential long-term profit. However, unlike investors, they typically do not take into account aesthetic considerations; rather they gather whatever quantity of coins they can and hold them. This is most common with coins whose metal value exceeds their
Doctrine of the Mean contrary to the course of the Mean." This guideline requires self-education, self-questioning and self-discipline during the process of self-cultivation. This principle was demonstrated in the first chapter of "Doctrine of the Mean": "The superior man does not wait till he sees things to be cautious, nor till he hears things to be apprehensive. There is nothing more visible than what is secret, and nothing more manifest than what is minute. Therefore the superior man is watchful over himself, when he is alone." This guideline requires understanding, concern and tolerance towards one another. Leniency was demonstrated in the 13th chapter: "When