An aphorism is a concise saying or phrase that expresses a general truth or principle. It is a literary device that uses a short, clever saying to express a universal truth. Aphorisms are often used to teach a lesson while speaking in plain terms. They are distinct from other sayings in their conciseness and how they express customary truths over universal ones with strong emotive connotations. Some examples of aphorisms include "A bad penny always turns up" and "An ounce of prevention is worth a pound of cure". Aphorisms are often handed down by tradition from generation to generation. They are used frequently in everyday speech, as well as in all types of literature. Aphorisms allow people to convey an idea or even a worldview using just a few words. They can make for excellent opening lines because they introduce big ideas in relatively few words.