nothing comes from nothing
From Lucretius, and said earlier by Empedocles. Its original meaning is 'work is required to succeed', but its modern meaning is a more general 'everything has its origins in something' (cf. causality). It is commonly applied to the conservation laws in philosophy and modern science. Ex nihilo often used in conjunction with the term creation, as in creatio ex nihilo, meaning 'creation out of nothing'. It is often used in philosophy or theology in connection with the proposition that God created the universe from nothing. It is also mentioned in the final ad-lib of the Monty Python song Always Look on the Bright Side of Life.