How do you fly with arms?

Flying requires a great many conditions to be met. For example, the limbs/surfaces that are used to generate lift need to be the correct shape, size and proportion to the rest of the body. Then of course you would need a sufficient method of propulsion. Our arms are not the correct shape to facilitate lift (nevermind the fact that our bodies are very heavy) and their surface area would not be sufficient to propel us through the air.