Epicureanism states that atoms are unable to be broken down into any smaller parts, and Epicureans offered multiple arguments to support this position. Epicureans argue that because void is necessary for matter to move, anything which consists of both void and matter can be broken down, while if something contains no void then it has no way to break apart because no part of the substance could be broken down into a smaller subsection of the substance. They also argued that in order for the universe to persist, what it is ultimately made up of must not be able to be changed or else the universe would be essentially destroyed.